EPA-AA-TEB-80-17
Effectiveness of Idle Adjustment on Light-Duty
    Trucks at Commercial Repair Facilities
                       by
                John C. Shelton
                  June  1980
          Test and Evaluation Branch
     Emission Control Technology Division
 Office of Mobile Source Air Pollution Control
      Office of Air, Noise, and Radiation
     U.S. Environmental Protection Agency

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                                   -2-
Abs tract

This paper describes the results of a project on Light Duty Trucks to evaluate
the effectiveness  of idle  adjustment  at  commercial  repair facilities.  This
effort  involved  a total  of 96  trucks  and vans  tested  by Automotive Testing
Laboratories (ATL) during  1979.   These vehicles were a subset of 370 vehicles
tested  in St.  Louis  as a part of  the  FY 78 Light Duty  Truck Emission Factor
Program.  Vehicles which  arrived for testing without limiter caps were chosen
to  participate  in  the  survey.   After  the  complete  laboratory  test,  a
contractor  employee  took  each  vehicle  to a  service station  or independent
garage  and   asked  simply   that  the idle  mixture  and speed  be adjusted  to
manufacturer's  specifications.   Upon  return  to  the  laboratory,  the  work
performed by the Facility  was evaluated  using  a tachometer  and garage-type
emission analyzer.   The  sequence was completed when the contractor's mechanic
performed the  idle adjustments to the best of his ability.  The data obtained
illustrates   the  inability  of  the majority of independent repair facilities to
properly set idle mixtures.  The results of this project point to the need for
mechanic training  in reducing vehicle  emissions through  correct maintenance
procedures.

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                                    —3—
Background

According  to  the  Clean  Air  Act  and  its  Amendments,  the  Environmental
Protection Agency  (EPA)  is  required to encourage and implement programs which
will  assure  that  properly  maintained  vehicles  will  meet  their  emission
standards throughout  their  useful  life.   Inspection/Maintenance  programs are
the primary force behind this effort to control emissions from in-use vehicles
with the work  to  be performed by  the  commercial  repair industry.  It is well
known  that  a  substantial  number  of  in-use  vehicles will  not  meet  their
emission standards when  tested  in an  as-received condition.   (Reference 1)
One  of  the  major reasons  is  that  the  idle  mixture  and  speed  has  been
maladjusted.    In  order for  these  vehicles to meet their emission standards,
these  adjustments  must   be  made  correctly.   The typical  places for  these
adjustments to be  made include dealerships, service stations, and independent
garages.

Purpose

This  study  was  designed to  evaluate  the ability of the  commercial  repair
industry to set idle adjustments to manufacturer's  specifications.

Selection and Test Procedures

Vehicles selected   for  this project  were  recruited  primarily  for  the  FY78
Light-Duty Truck Emission Factor Program.  Trucks  which arrived at Automotive
Testing Laboratories'  (ATL)  St. Louis facility missing  idle  mixture limiter
caps were  chosen  for  this  study.   Ninety-six  out of  a  total of 370 trucks
tested  which  had  their  limiter  caps  missing   were  taken  to  .commercial
facilities by  various  persons  in  the  ATL  organization  (secretaries,  lab
personnel,   engineers,  technicians,  etc.).   The   following  procedures  were
employed:

Before Leaving ATL  -  Vehicle  identification  information  was   recorded  on
worksheets provided by EPA.   Idle readings (CO,  HC,  RPM)  were  also measured
and recorded.  Any evidence that the vehicle was  in a testing program (e.g.,
data packets  or  exhaust  connectors)  was removed  from  the  vehicle.  A repair
facility was contacted to set up an appointment to  have idle mixture and speed
adjusted.  If  possible,  all  adjustments were to be performed while the driver
waited.  No reference was made to any affiliation with an emission testing lab
or that this was  to be part of an EPA study.

At Repair Facility  -  The person requested  that the idle  mixture  and speed be
adjusted to  manufacturer's  specifications.  If questioned  why, it was stated
that they had  been informed in some way  (by a friend, magazine article, etc.)
that this is a very important adjustment from a number of standpoints, such as
fuel  economy  and  engine performance.   If  the  mechanic insisted that other
maintenance be performed, it was stated  that the  person wanted only the idle
adjusted at  this  time to see  what difference it  made.   If the mechanic said
that he  did  not  know how to set  it to specifications, he was asked to set it
as  best he  could.   Notes  were made  (although not  in his presence)  of any
comments  and  actions   taken   by  the   mechanic.   Observations  regarding
instruments,   tools,  and cost  data  were  also recorded  on  the worksheets.

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                                     -4-
After Returning to ATL -  ICO, IHC,  and IRPM were .measured and  recorded,  as
were the number  of  % turns necessary to lightly seat the idle mixture screws.
The mixture  screw  settings  were not measured prior  to  sending the vehicle to
the  commercial  repair  facility.   Idle  parameters were  then  adjusted  to
manufacturer's specifications  by ATL  mechanics  and the  location of  the idle
mixture screws relative to the lightly seated position was recorded.  ICO, IHC
and IRPM were again measured and recorded.  New limiter caps were installed in
the center position.  The vehicle was then returned to its owner.

Follow-Up -  ATL  personnel  performed a  follow-up  inspection  approximately 30
days later.   The presence  and position  of  the limiter  caps  were checked at
that  time.    The owner  was  also  asked  several  questions  relating  to  the
performance of his vehicle.

Results

Idle tests  -  Nine  1979  model  year trucks were  taken  to commercial  repair
facilities.    The results  of  these  adjustments are  summarized  in Figure 1.
After  adjustment  at  commercial  repair  facilities,   idle  HC  concentration
increased by  80%   and  idle  CO  increased  by  50%.   The  engine   RPM values,
representing   the    average   absolute    difference   from    manufacturer's
specifications,  were  essentially  unchanged.   The  average   cost  for  these
adjustments was $2.17.

Eighty-seven  trucks  from  the  1975-1978  model  years  were  also   taken  to
commercial  repair   facilities.    Their  results  are  summarized  in Figure  2.
After  adjustments   at commercial  repair  facilities,  idle HC  concentration
decreased by  25% and idle CO decreased  by  9%.   Again,  the engine RPM values,
representing the average absolute difference from manufacturer's specification
were virtually unchanged.   The average cost was $4.23.   Almost one-quarter of
these visits resulted in no charge.

A  follow-up   limiter  cap  inspection was  accomplished  approximately  30 days
later on a  total of 82 trucks.   The new limiter caps on 55 trucks were found
to be unaltered.   Limiter caps had been removed on 22 trucks and 5 trucks had
their settings altered with the limiter caps still installed.  The results of
the follow-up are summarized in Figure 3.

The results  of each of the  96  trucks involved in this project are listed in
the Appendix.

Results  of  the  Federal  Test Procedure - Although  the  Federal Test Procedure
(FTP) was not performed  on these vehicles after they returned from the repair
facility, the FTP emissions for the  fleet were collected and averaged based on
the presence  of  limiter  caps upon arrival at  the  laboratory.   These averages
are listed in Table 1.  The values here indicate that vehicles without limiter
caps have  average  HC and  CO  emission levels  which  exceed   those where  the
limiter caps are intact.

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                                        -5-
Conclusions

1.   Only minor adjustments would be required to allow most vehicles to pass a
     basic I/M test.

2.   The commercial repair industry does not currently adjust idle mixture and
     speed properly.

3.   A  lack  of  training  and  proper  equipment  (tachometers  and  exhaust
     analyzers) is  apparent in  the performance of this  type  of maintenance.

4.   In order to conduct successful Inspection/Maintenance programs, some form
     of incentive or  a  major effort in mechanic  training will be required to
     ensure that idle adjustments are made properly.

References
1.   J.T.  White,   "An   Evaluation  of  Restorative  Maintenance  on  Exhaust
     Emissions  from  In-use  Automobiles",  SAE  Paper  780082,  March,  1978.

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                                     -6-
                                    Table 1

       Emission levels and Fuel Economy versus Presence of Limiter Caps
Model Year(s)

1975-1978
1975-1978
75-78 Totals
1979
1979
79 Totals
Limiter
Caps on?

  Yes
  No
  Yes
  No
1
159
100
259
95
15
110
HC_
3.73
5.74
4.50
.97
1.17
.99
CO
39.3
58.9
46.9
13.2
14.2
13.3
NOx
3.87
3.88
3.87
1.89
2.02
1.91
MPG
12.7
12.1
12.5
12.9
12.2
12.8
HFET
16.5
16.0
16.3
16.5
16.5
16.5
IHC

240
380
290
 76
103
 80
ICO

1.4
3.5
2.2

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                                   -7-
                                 Figure  1

                     Effectiveness of Idle Adjustments
                      at Commercial Repair Facilities
                        Nine 1979 Light  Duty Trucks
        200 _
 IHC     100 _
(ppm)

          0 _
                 189
                  105
                                 136
                                                 3.0
2.0 _
                                % ICO   1.0 _
                                          0_
                Before  After  After
                Repair  Repair  ATL
                                                                  2.1
                                                  1.4
                                                                .33
                                                Before  After   After
                                                Repair  Repair   ATL
                                                 100 -i
        100 _

 IRPM*
         50 _
          0  .
 * These numbers are the average absolute
 difference from manufacturer's specifications
         24 -,
         20 -





]
1

83




Before
Repair


7S



After
Repair

75 _
Percent
of
Sample
24

After 2b
ATL
0_








Sfi7








_Average Cost $2.17
22%
11%.. ! 11%
i
                                                 Free  up to 2.01-  5.01-
                                                       $2.00 5.00  10.00

                                                    Cost of Adjustment
 Number
   of
 Trucks
         16 -
12 -
          8 .
          4 -
          0 -
                                        [|   1975-1978 Models

                                        g£3   1979 Models
                                                     17
        2    0    2     4     6     8   10
     Richened     Leaned
     Number  of  % turns required for proper adjustment after return from
     commercial repair facility

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                                   -a-
                               Figure 2
                  Effectiveness of Idle Adjustments
                    at Commercial Repair Facilities
               Eighty-Seven 1975-1978 Light Duty Trucks
                  393
tuu
IHC
(ppm) 300'

200.
100.
0.
!
1












295






238



4.O.,
                                            % ICO
                Before  After  After
                Repair  Repair  ATL
                                                 3.0_
                                                 2.0.
                                                 1.0.
                                                          3.3
                3.0
                                                                          .54
        Before  After  After
        Repair  Repair  ATL
*IRPM
       100 -
        50 -
                                            100'


                                             75
                                                                    — Average Cost $4.23







86






yo






Percent 50-

of
Sample
25

17
1 o










22%








7%


•3Q7|
jy /o>
\

1




777.








5%
	 J
                Before  After  After
                Repair  Repair  ATL

* These numbers are the average absolute
difference from manufacturer's specifications
   Free  Up to 2.01-  5.01  Over
         $2.00 5.00  10.00  10.00

         Cost of Adjustment

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                                  -9-
                               Figure 3
       Results of 30 Day Follow-Up Inspection and Questionnaire
                Eighty Two 1975-1979 Light Duty Trucks
Limiter cap status at 30 day
follow up inspection
       100%-,
                                                    Satisfied with present performance?
        50%_
         0%.
                              150%-,
                  67%
                               50%_
                           27%
                                    6%
                                0%J
                                                                  91%
                                                                           9%
                 same   missing  adjusted
               position
                                                                  yes
                                                                          no
Is performance different than before test?
       100%,
                           74%
        50%_
         0%J
                         Has there been a change in fuel economy

                      100%.
                   15%
                       50%.
                                   11%
                                                                  69%
                                                          15%
                                                 16%
               Change
               for the
               worse
  No    Change
notice- for the
able    better
change
Change for   No    Change for
the worse  notice- the better
           able
           change

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      -10-
Appendix

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                           Before
 Vehicle'               Repair Facility  Typo of
,,JjaibFy.^U!ib&UiatL-'A'~Ilj.9. ^n _.lm'*  r^-m ty
                                                                  rffectiveneR8~oi Idle Adjustments
                                                                   at CommerclaL Repair Facilities

                                                                       F/*?3 ,££ .4*4*1 * T^^fter
                                                             Service Person's                Repair Facility
                                                               •Cor.jnic-nts  '          ,    Co.'it  IliC ZICO  JKI'il1''
                                                                                                                                                                •i
                                                                            Differences' in
                                                                    '         !5 Turns  o£
                                                                Lab Set     Mixture Screws''"''
                                                                       t.UPM   l.crfl: Ui.;;h'.-
                                            Aildltioail
                                            C;)-.i;r.'.-.nt:'i
                          - -3,93-
                                                                        #off£
                                    o
                                                                 ,2«r  730
                        /fc
                        It.
                                                                                                                                    //
                                                                                                                                    /T.
                                                         ''c   look'td
                                                hood .of *i
                                                    ,'clt  *M Kun
                                                    y;J*lt»tt
                                                          zs* -  .IO-
                                    A/tf
frw)
                                                                                               •jood
        fiord-' floO
                      *>*•- -of ~
                                                                              10  •   10
                                       j
                                                                                                      (-too.
                                                                                                                                          3-ftt
                                                                                                                                          5 •/<
                                                                                                         /
3/3/7?
                                                                                                                               n
                                                                                                                                9
                                                                                    /o
                                                    (.-f/oo)
                                                H-i
                                                                                           1*0 .-,.30 -
                                                          .2oo -.30 -570
                       //      "j
                                                                                                                                         5/,
                                                                                                                                                    * t bi(f n
                                                         e vehicle'!
                                                                                              a tJ\\t{t*,tH-is. .
                                                                                             nr  Ti Gonif-gtktnun •
                                                            rejvrej  ~6
                                                                 rt^"/*
                                                                 T/
                                                                 t*
                                                          ^00 -
                                     (9
                        tf
                        /*
                                                                                                                                     If
                                                                                                                                     /y
                                                                                                -5.0-
                                                                                                                                         u/»* poor
9095
                                      "Tcyofo
                       IHC  7JCO
                                     0
                                                                 - .10  goo
                                       »b./ f y
                                         3-fT-fe
      AVEKACJES
 '•'Number shown in parenthesis  is
•  the difference in RH1 from the
  ir.onuf acturers specifications .
     grcatcr thcn,-!-lf'HS tlu-'n).
                                                                                       cost   me   raoo   IKWI*  JUG   ;;ico
                        _;._	:  . Cfi W
                         Lolt  RiEilt ftft'V1  » nusibcr of Ttura
                                      in  the "rich" dirrcti
                                     "-"  = nuriber of 'i turn;
                                                                                                                                                r:ic  "l
                                                    divocri,

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                                                                     lif fcctivcrtOPHrfff~Iclr. Adjustments
                                                                      at  c
                                                                                                                                                                  ... ._!
j;-  , Date i

j|  Vehicle

i ^&%kP.L..-i&&g-&
                                   .
                              BQfore
                          Uepnir Facility  Typo of
                          IHC%ICO  IRVM*  Facility
                                                               Service Person's  • •••'•
                                                               :   Consents     :   :
                                                                                                        Difference*!,,  •
                                                                                    .                     Alurn.sof    ^
                                                                       Rep.iir Facility      Lab Set     Mixture Screws **
                                                                 Cost  IHC>,IC'J  ::::!"   IJJC /TICO  IRPM   T.c.'r. R;,-.:'.v
                                                     Additional
                                                      Consents
                       7Z  -i.
                                                  fltte/ity-fc
                                                          d
                                                          V'45-
                                                tzi "too*
-.25 -
*• .25 -100



     >  {-So
                                                                                                                                 .   7   •  -
                                                                                                                                             f)/f
                                                                                                                                                                  a.
'*/lfa
                                        i-farfibn
                                                                                              Sop - 1.0 -
                                                                                                                   - .20 -
                                                  lf>tC*9r)i'£  S«>;a  •/(,,. ..-,.-. ,.f  .
                                                                tJiikptJ. ftJySita
                                                                                                                                  10
                                                                                                                 /5

                                                                                                                 II
                                                                                                         (+5oo
                                                                                               US- 2.1 _
                                                          «
                                                                                                                                   I   •   1
6/20
                                 -700
                                        St^f/
                                             ovi
                                                                                                                is-  -<>y-  700
                                                                                                                                   / o     to
77?
                                        Sar-j
                                                  Heei
                                                                                                                                                  /i   *«**»*/
?h/2i
                           -2,76 -
                                                                                                               / 300 -,i5 -
                                                                                                                                              n
                                                  r»«e /)a^»'c  uiej  aw // - i, ie. 4  *« iV.t
                                                  3*1rli/lft/ -/itti/ha /'t/ff t+l'IffHb"
                                                  ° "i.c'riC' .^•|v*.'"7i   j"/    T
                                                                                                                           (+10°)
                                                                                                                                             •frit m  stop  -/Ton-, -fair
«I35
           *J
                                                                                                                                     f    I
IHC  ZtCO  IRPM* .
                                              _jy.ii&.,-.jfti[fi..
                                                                                                               7V<>  - 1,0 -
                                                                                                                                  "a.    0
       AVKKAOES
                                                    '-Number shown it/ parenthesis  ia
                                                   •  tlie difference  in RFM  fron the
                                                     manufacturers sj>ccif acntions<
                                                     (H-"j;rcafcr thc:i,-=.l-:i>f:  ii).'!n)
                                                                                         Cost  IHC  SICO  IKl'M* JHC   ZiCO
                                 to it MjCJ!i*<»"+" - ncr-.bor of !£

                                               in the "rich" d.irocti
                                              "-" ° r.unbcr of '< turn
                                               in tiic "lonv." divecti

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  rt '-f-,rr
                                                                              '3&
 ,       ^
  Vehicle
           M;ike
                            Before
                         Repair Facility  Type of
                         IHCXICO  'IRVH*  Facility
                                                                    Ff-
                  nffcctivences of Idle Adjustments
                   at Commercial Row ** J^}"^".^
                         -7&~^T.  £<*m  /*<$££
                                           Repair Facility
                                     Cunt  1IIC21CO  IKHI*
Service Person's
   Comment.",
              Differences in
                * Turns of
   tab Set     Mixture Screws**
JIIC '/, ICO IRPM    I.oft Hi. .-.],::
A»!dlt:I.oiinl
 Consul:;:
  v\\
                                               fecfomc
                                               a
                                                                       "ff
                                                                                  tl.bo
                                                                                              -l-7-t.io

                                                                                                   {-no.
                                                           /oo- .70- 75' -8/0
                                      Sunoco
         • J
foec.n)hi'e.
ta»i  twa
Uj,«A
>« «••'(-
                                                                «»e
                                                                                                          /feo-  ^5-75-0
                                                                 7.   •
                                                                 3     3
                                                                                                                                       t,
                                                                                                                                      a
                                                                          1-fov  tob.'vwf
                                                                          Crdl/  "to fWa,
 W?  forj-F/op
                    MA -W^
                                                                                                                           10   /3
                                                                                                                                         i »»>/»« e/ji^V' rff/j
                                                                                                                                         j
                                      Te/ac
                                                                           Jec«.
                                         3-75
                                                                                                                                     /l/o   Dtff r
                                                                                                                                     A/f crtfajr/trt a.od(/
                    46-
11171-
                                                                                         500 -y. 5  -
                                                               - .V r-
                                                                            12.
                                                                            li
                                                                                                                                  it
                                                                                                                           zo '  n
 'kiln.
\llll
                                -te* Shelf
                                      Stettin
                                                                                                         US - .
                        me   2ico  rera*
       .AVERjVOES'
                                                 ''^Number shovn  in paront.hes.ts is
                                                  the difference in RIM from the
                                                  h.inufacturers specif acntions.
                                                  (H-™j>irc:itcr  then ,-~.1.o:;s th(:n).
                                                                                    Cost  IIIC  2ICO  1RPM" IHC  %ICO
                                                                            /Z    '

                                                                            Teftm
                                                                                    !Jli.>v«r"+" = uunbcr of k turn
                                                                                          in the "rich" dlrncti
                                                                                         "-" «• nunbur of !i tuvr
                                                                                         - in L:-.!- "lOiir." ditccti

-------
  Dace  £.
Vcihir.la
                             .li-  rx-.ility  Type  of
                             .-:u:o   IIU'M*'  Vacilil-y
                                                                                   -14-
                                                                    Effgctivoncus of Idle Adjustir..::-.ts
                                                                     at Corai.-.orcial Repair. Facilities
                                                                        F/: 76-
                                                               Service  Person's
                                                                 Common l«
                                                                                                                                           t,t  *n  reilty
                                                                    ^i>-  H«  rat «
                                                                                              4,00 - %.o -
                                                                                                                                  /y
                                                                                                                                           ft/I
.$1*/21
                                                                                                                                 /O    //
                                                                                                                                 / o   ia
                                                                                                                                             e (ae/iy   i
                                                                                                                                              ifL'.fe. J/t e
                                                                                                                                                 ata.
4 its
                                       Sunoco
                                                                       s;d«   «
                                                                      ff  a
                                                                      «
                                                                                                 - 5.0 -
                                                                                                                    - /. 7.- 6> SO
                                                 Used
                                                      /t/J
                                                                                                                                           'O^tltfy o-f .
                                                                                                                                           /».». 1
                                -700
                                                  ho
                                                                       t»o/
                                                                                                  -6.0-400
<}6o-
                                                                                     {{7,00
                                                                                                                                   (o     ~
8/75
7/33/77
                                      She/I
                                                tr»etAi>,/c.   fa/of
                                                                                                                                  17    ZO
                                                                                                                                  n    i
                                      SAelf
                                                                             Jf
                                                     ho
                                                        ic  bto*),ei'tolW'r*i
                        T.IIC
                                                                                                         -700
                                                                                                               75- -02- 500
                                                                                        , So
                                                                                                                                  10     10
                                                                                                -  .sz-?oo
                                                                                                               65-   -So- 606
                                                                                            	(±/oe) ._.
                                                                                                                                  10   — ,
                                                                                                                                                             .
                                                                                                                                                           (e°0»''
                                                   -i.'iir.'.bcr shown in parenthesis is
                                                    the ilif fnrencc in Ul'M from Uho
                                                    mjnufar.lia'ttrii specif acntio:.;;,
                                                    (H--;',i:c:itcr tlicr, ,---O.«:.'is clu:;i)
                                                                                        coat  me  2ico  iiU':-» me  zico
                                                                                                                                  LU
                                                                                                                                             .v,.v. ... numbcr of h turn.
                                                                                                                                               in the "rich" dirocti
                                                                                                                                              "-" = nur.ibo.r 'ot '; turn
                                                                                                                                               in thc-'Miv.!'.

-------
                                                                     Effectiveness oTIdle Adjustments
                                                                      at  Coimnavcial Repair Facilities
 \   Bate &                    Before
 ;  Vehicle                 Repair Facility   Type of
 ,  ;-;i;i::i;cr   M:.iV.i: fcModel   IIIC /;tCO  JIU'M*   Facility
' J-•*'.''»y'_'^j •••>_.—^•g>-f^-JL~i''T_"'^'^""- ' "-I'tTT^-TJii i    	--_.-!.. _-uj-L •-.	.i-ji^_-n.-j.-. ;- J
                       33  -.56
                                                                Service Person1.1?
                                        Difference.'!  in
                                          *4 Turns  of
      Repair Facility      Lab Set     Mixture: Sc.ircw.i'
Cos!:  1HC %ICO   IRl'M"*   I1ICX1CO  IRFM   I,-,!'c K-?'*:
 tf/95
                                 r.
                                   c/i,
                                                                                        ff/Z.So
                                                                                                                              (+!•)
                                                                                                                                     /z
                                                                                                                                  /VUIit.l.on.1.1.
                                                                                                                                                                     **
                                                   o/f
                                                                 II.
                                                                                               /so y,?o
                                                                                                .0!   <(
                                                   ti '>fO
                                                                        50  .
                                                                                                                 50  .50
                                         ti i^ctl
                                                                                                                              (0)
                       /OS
                                          '0
                                                                                                           .600
                     /oo   >C t-  500
/o
/o
//
10
                                        lA/O
                                          'b 3S-po/*>7'i
                                                                                                                 no    , of  700
                                                   tii/r-0
                                                                                  (w)
                                                                                                                                     5-    5-
                                                                                A/AS
                                                                                                                3?0    • 20
                                                                                                             «?      8-
                                                    /v h
                                                                                                        (•ftfo)
74/0
             - C20
                            u/ tp/u'tf
                                1     '
                                                               tt'D TVwt/fe
3 3P- 7, (, -500
                         T.IIC  /:tCO  IRFM-
                                                                                                                       .so •  7to

                                                                                                                             frico).
                                         //
                                                                    j KfSl/fQ
                                                                                               V/o
                            -9-0   7to
                                                                                                                                    /P.-
         Xi-.AiM'lS
                              ''•'N'lir.ibc): sl\ov.-n in parenthesis is
                               r.lu1 (Mllfuroncc  i:<  Ri"! from tliu
                                                                                           cost  IHC   rato   ii>rc.-;to.r then ,-"'i.c:;::  t!-.. :i
                                                                                                                                       --^ il-L&ilL--':'<"•!•" = ncnbcr of 's turn
                                                                                                                                                    in tho "rich" dirpcLl
                                                                                                                                                   "-" = nii::.'.--:;;: of 'i turn

-------
                                                             -In-
                                              effectiveness  or lule Adjustments
                                               at Coir.naro.ial Repair Facilities
  l)atl- ''
Viiiir.l.o
    Before
Ro.|):ii.r  Facility  Type  of
Service  Person's
   Comiiionts
                                                                    O«-.r
Repair  Facility
UK'. 21C.I1   IK:1!!"
   Lab Set
IMC. 2 ICO   IRFM
Differences in
 l-t Turns  of
Mixture Sr.vcwa *'*
  I..'ft Rir.liv
Additional
 Ccnir.cn l" s

;.72./7
•S////79
,








^^
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•



.v;:-,.,KS

/2' /fW."%r0
l$7-2.%-4OO






me ;u.co IRP:


II
Sf * 6









iJi'.Ln<.i'.[ ZDlk. />#•> A'JJJ'; ^tiMvfy
MfC/SA'iStL 9/)fP IDLE To F/t$/'




-

**;Muniber slicv/ii in p.'iriinthGii.s is
tlio djfforcnce in U1?M frori the
manufacturer ^ spcctfacatlons.
*. • (,l C. tt ti... t IK.u , . .i.t...... tlK.il/
O,OO
l.oO






Cos


//£ /,io /^o
i/OO o ./A" -7^0
/$& -o 2- 7 So




• '

i* liic %ico


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> . -
•



.
( . .'-
Left Riflh


/I/O P/ FffZf-'VKif'-
t
A ,&:•«+.
' •]



• •. ^ •
...... ( ,

in the' "rich" divocti
"-" = nir.i'eer of -t turn
'in ;::;•• Mean" JlracBi

-------
                                                                                    -17-
                                                                     Kf(!octtveno.':s of Idle Adjustments

                                                                       at  Cowir.arcinl Repair Facilities
     Da«*                    beforc
 ;  Vehicle        .        Repair Facility  Type  of  .
   ;;u:::b.;r   Iljike JcMs.\lol.   7110 MV.O   IKI'M''  r.-ir. il.lCv
                                                       Service Person's

                                                           Coira-u-ntn
                                                                                        ***,- 4«
                                                                                         :;ln..
                                              Repair Facility       L.ih Set     Mixture Screws'11*      A(Ulii..i...:wl
                                        Cost  T1ICZICO   Mil':;-''    T.IIC 7, ICO  TRf.V   i..:i> r,:-,ii!           i>r>;r--Mi-s
                                         Mo 6/1
fflecfito'C-. "»"*" f"fr  A*'^ i/_ ««"j[/f FA
t  It 't  lib •*•»«» •aa^fif'T tl*tt€ TC/fctC I
<*  '^.\l   /     ~J* ~ Jt*^ /  *  / Ji .\J
   At J '9  n ul  W C.HI 9f/Cait- & *j& W'b-
   at /it'.   L.       ^ fM° ^   t    * * ft
frl cJ/A *l*  t*K.&*ft .^r1  •&**¥  ftlt J.OO
                                                                                                                  -- (,
                                                                                                                                               >y,iffi+e.  ft I/ •'  •  i :

                                                                                                                                               end /ui h'»M s - -fj ir
J7/Z5/7?
Uojee.- t>IOO

                                                                                                                 12 S   -V-  7fo
                       /SZ -3-03 ,
                                                                                                                                       tJo   J>- Tfettnt g

                                                                                                                                                    '
                                                                       **•/  /

                                                                          <7
                                                                                       1oo- f.ti-
                                                                                                                                           /3
\1Z*1
                                                                                                   - 3.3-700
                                                                                                         75-  .03-6TO
                                                                                                                                       /l/o
                                                                                                                                    /o
                                                   /wec/fWci I4/W
                                                                 •
                                                                                       75--OV-730
                                                               50-
                                        /7
                                                                                                                                                           .
                                                                                                                                                         fi/%.  •*'
 7/6/7?
                                                   fWee/itH,t
                                                                       ft~t
                                                                                        J.ao
                                                                                               -ss*


                                                                                                 (-/oo
                                                                                  //  •   /fa-
                                        5/dHc/jJ
                                                                                                              -  .5-
                                                                                                                                     •//  "  10
                         1HC   '/.ICO   IRVM"
                                                     '''Number sliov.-n  in  parcnthor.i.s  is

                                                      the iliffcrcncc In  Kl'M from t!ia

                                                      sonufacturers spccifacatior'.s.

                                                      (H-~j'-1-"e-"-cr  tlu.n,-".l.e:-;.r; then)
                                                                                           Cost  IHC
                                                                                                                        HCO
                                                                                                                                          in th>. !'rich" dirrcti

                                                                                                                                         "-" = nur.focr 01" !£ turn

                                                                                                                                          in thr "It.!"!1.-." tli.rccti

-------
                                                                               -18-
                                                                            csa of I
                                                                  Effectiveness of Idle Acijustnients
                                                                   at Comr.arcurl Renair Facilities
  •Vehicle
                             Before
                         Repair  Facility  Type of
                         TUC  W.?.  T.R'.':.!ft  FariUtv
Service Person's
   Coir.nu-iii.-J
        Repair Facility
   Cost  II!!J?;I~0  JRS:""
                                                                                                                 Lab Set
                                                                                                              JHC •;:!«  T.UFM
                                                                                                                             Differences in
                                                                                                                              •i, Turns of
                                                                                                                             Mixture Screws**
Additional
       f.l--
                                       She.//
                                                    Jnc/
                                                                      tit
$7,00
                                                                                                            Zoo-  .? -
                                                                                                                                             *
                                                          iff* ten c
                                                           f J'*-je
                                                              J
tys/7?

                                                                                                                - . 5 -
                                                            *
                                                                                                      /zo
                                  ft/00}
                     3oz.-S.V1-
3/.2/21
                                                                                                           35V?- -5  -
ifaft
        thef- CIO
                         -t,,63 - (,00
                                                                                                                                         were  -fair.
                                                                                                           75 -
                                                                                                    &30)
                                                      object./ t'/lH"
                                                                                          ns -t.
                       300 -/;y  _
                                                                                                                              ft,  •
                                                                                                                              //
                                                                                                    (-<*:
                                                                                                                                                 -«
                                                                                           30* -
                                                                                                                - »oV- 600
                                            x.  /<>•
                                           •7-*  ff
                        Ii!C  21.00  IV.VM*
       Av;cKAr;i;s
                                                   •:Kur.:ber shov.-fl in parenthesis is
                                                    the  tlif forcncc in RPM t"ro;;i tho
                                                    naiiufacturers spcicifncntiQns.
                                                    (•i--'i'.rcr.tcr thcri,-»lcas than)
                                                                                                                                                 floo..
   Cost   II!C   ZICO  1-ltPM* IHC  ZICO         Loft il3!lL:v,v".|.'' = ncr.ber ol k turi)
                                                        in the "rich" diroct?
                                                       "-" •> nur.iber of k turr
                                                        in tiie "lean" dirccj;!

-------
•I   U;!te "                   Before
  Vehicle                Rnpair Facility  Type of
 L.u^!^^L,..J:!a^Jii!afeL..-.Ilic ^Ico  lR^ft  Facility
 .
     Effectiveness bTTdle Adjustments
      at Corair.::rci;il Repair Facilities
       fy-ia-ST.ionts   -    "
Service Person's
   Corn-lent s
                                                                                          After
                                                                                     Repair Facility
Lab Set
                                                                                      Different-fin1 in
                                                                                        !i Turns of
                                                                                      Mixture Screws**
                   - s://- 700
%&!/
                                                                               Cost  IHC %1CO  lUi'H1''   IHC J!ICO  IRPM   Loft  F.xijhf.
Additional
 Co'."ients
                                                                                                             300 -
                                                                             Jjlt -fuA
                                                                                 Xood
                                                                                                                                                 -fair
                                                                                        - 7.0 -
                                                                                                                        /t
                                                                                                                         7
                                                                                               Id
                                                                                                7
                                                                                                                                           /(/tf
                                                                                                                                           iff
Ihrt-fto
             1780 -7.0S- 580
                                                        - .85-700
                                                                                                                                 '/     I/
                                                                                                                                  7    7
                                                                                           b.k'f'Y
                                                                                           atY-  Co
                                                                                           1t>.^e
                me  zico
                                                   shown in parentiiosl;;  is
                                            tlic difference in  RPM fron Lhc
                                                    urcrs specifacnuions.
                                                   .or tlicn.—-.1.f-:.:s t!;c:!-.)
                                                                               Cost  JilC  %ICO  1RI',"." IHC  ZICO
                                                                                                     ^" n nunb-^r  of k  turn
                                                                                                      in the  "rich" divncti
                                                                                                      -" = nur.iber  of k  .tutrr

-------
   Vehicle
        lie fore
    Repair  Facility  Type of
    Till".  2H:0  IIU'M"  Faclli'tv
                             -20-
                I'.f. foclivencf.s' of  Idle Adjustments
                 at Coiacarcial Repair Facilities                          Differences in
                  fi-TQ $7, Lorii Tfatit'*       After                        -'s Turns of
           Service Person's                Repair Facility      Lab Set     Mixture Screws**
              Convener;               Cost  IHC 21CO _ IRl'U*.  IHC Z ICO -IRPH    Loft R.i.shf.
                                                 Atldition.il
                                                 Corar.cnts
                           - .3  -
                                                                                         (ZS   /.6l
                                                                                                     (o)
                                                                                               .  (0}
6370
                           flit 'if/we
                      C*eti.
           50  '80   750

                        (0)
                         6
                         y
6^73

V5/79
/
                                                     ft/7£/
                                                        /•TO
                                                                                                   (.to)
                                                A/P
                                                                                   5.00
                                                                    too
                                                   50t>
                        mo
                                                                                                       	
                                                  '•N'umbcr shown in parenthesis is
                                                   the tliffcronce in lU'ii from the
                                                   •.r.anufacture.rs specif'. mentions .
                                                                 cost  me  ;aco  IHPM* me  zico
                                                                           Lefl: M£]lt ft*"v „ iu:r;lbcr oi >j turil
                                                                                        in ti;o- "ric'x" dirocti
                                                                                       "-" = nunbcr cf !; turn
                                                                                        ii: the "le.-i!i" uiract^

-------
    Date £•                   Before
 '•Vehic.le                Repair Facility  Type of
 .,.,^!^-ji.i:.^JJil'-c-&;-!pc!c.l.	IHC %ICO  IIU'M^  tVicility
f//W^7
                      325 -7.05 -£,2,0
                                                           F.ffectivenor.a' of Idle Ailj'.iftir.ents
                                                            at Commercial Repair Facilities                           Differences in
                                                        FY-78   S7~,  tov\j  7,'?VCitS      After                        k Turns of       .  f>
                                                      Service  Person's                Repair Facility      Lab Set     Mixture Screws'**      Additioail
                                                         Comments               On.-.!:  TilC %ICO  IU\\':'   IHC 2 ICO  IRPM   I.oft K:li:h:-,      	Corrr.cr.ts
                                    \r.oo
                                                 smaU
                                                                                     300
                                                                                                 -2.05
                                                                                              IsL
                                                                                           •/06
                                                                                              500

                                                                                             (-loo)
                                                                                                    156   Z.
                                                                                                         ;# LL
                                                                                    50
                                                                  • of   hoc
                                                                                                                       'V
                                                 metJiaitic.Si'J oefi.J
                                                 <;<
-------
    Date i.
   VV.hic.le
                      liefore
                  F.npair Facility  Type of
                  1:10 /;ICO  IRl'M*  Facility
                   -22-
              inosij' of Idle Aujuatmints
      at Cor.«.:rcial F.cp/jir Facilities
       fy-?e  57 (Mil ' 7M& -  Afuer.
Service Person's                Repair Facility      Lab Sot
   Coni:v.v.t-.:;               Co.'St  IllC % ICO  IK!"."''   IHC "ICO  I
                              Differences' in
                                k Turns of
                              Mixture Screws **
                                l.cft Rlr;!ii:
                          Addition.il/
                           Comments
W^-
                                 -feo
                                                                                       Q.Oo
is?//
?/i e/.- 020
                       210- .
                                                    sst'/o  77//y./
                                                                                       f.oo
                                                                                                 /.ol   7oo
                                               3oo  .70
                                /    -of  6/0
                                        '•***•*
                                                                  7
                                                                  la
                                     JO
                                     to
                                        ftM
                                          me (ton flit  sw/o /^/ ^/T ///«
                                          .XW/P  /^ ^*i i   Of-f"
                                                                                  /«*
                                                                                   •*
                              3V6
                                                                 if     /.
                                  -700
                                                                                                                                      '17
                                                                                                                                      i\ti)
                 inc  ;.'.(00  IKV'M"
                                            •::\'ur,\ber shov.ii in parenthesis is
                                             tlio dj.fCur^nco in Rl'M from Che
                                             ra.ir.uractuvers spcciiac.itions. .
                                             (H-==;jL-cater then,-:-lJ:Kj. .timn)
                                                                                         cost  iiic  ;aco
                                                 IllC  IICO         left Right ,^..+.i r. iu:nibcr of ;,
                                                                                 ii> the  "rich" d.lr«ctt
                                                                                "-" = nur.ber of .'i turii.
                                                                                 i:i the:  "loan", difacti*

-------
 i.  U:ll:c &               •    Before
 ;  Vehicle                Repair Facility  Type of
 L..-iU!I!'a<-:i?	,:J!i'jP-.(!.::tfiiL'?i.^..jj|g %ICO  im'M*  Facility
                                              Effcctivcncss' of Idle  Adjustments
                                               .it  Commercial Repair  Facilities                            Difference.'; in
                                         f-^-TB   S7. tQUtl^   -ff£u(({'f:>    After                         k Turns of
                                        Service Person's              •  Repair Facility      Lab Set     Mixture Screws**
                                           Comciitg               Cost  IliC %ICO  ir.!'M"   IKC ZICO  IRPM    Lett !V.; r.:V.
                                                                                                    Additloail
                                                                                                    CCTJracnls
                                                  r»
                                                        M>
                                                                                                              * S<»
                                                                                                   boo
                                                                                      8
                          - 2.76. 5-50
                                                                                                          if     //
                                                                                                          /o     V
                                                                        "trrr#
                                                                                                                                            t'V
                                                                                                                          SSL
 5327
                  T/ffMO
                                                                                             WS"  A
                                                                                                                    °3
                                                                                                          /a.     '3
^3321
        fad- f ISO
W- 2.07 -55Q
fl/irfW/vit S-Vi'O H(. fan M 0 ill  4-(Yl P
                               IJ%
                                   To
(o
                                           AST
55t>
                                                                                                                                //
>n>t>f,/;F/v/-,
, /.    ' ' U<-< ( *
                      IMS- +t oft -300
                 (MM*
                                                                                      3. 00
                                                                                     //
                                        SHtLL,
                                        SK-  .
                                                                                            /, oo
                                                                                It-   12.
                                                                                11.   >1-
 5339
.y/g/;^
J53VO
                                                  MfCtffMiC sfiit)
                                                    BULK TO
                                                      T^CH.d
                         I!IC   XICO  IRPM'1'
        AV;;;
-------
                     -24-
     l!i fcctivsncss of Idli: Adjustments
       at  Conwcrcial Repair Facilities
  Date i                    Before
Vehicle                 Repair Facility  Type of
 Kai.ihor  M;!!;r. -Ji^kl   IHC 55ICO  IIU'M''  Facility
Service Person's
                                        Differences' in
           After                    .      k Turns  of
      Re-pair Facility       Lab Set     Mixture Screws**      Additional
>.-!;  l!!C p:id)  'Ifav!'v    IliC % ICO  IRPM   Left R.ir-!-.i:          Consents
»I'M
XI
bT'lr/
5»1
*/0






isr^

V^«

•
* .



349- 

?3-2jy -700



me 21 co izn

W'n^<, .
MS
s7/ir/oV
7£/fl(o
AJoBiL
™p.





W-*~ f-> Sc ft*vw> t'/c-ii/C/J.
hilHAiJiC- SAi'D frt/?4J .ivrt-i o^/ o?
^ hi . ft\A\ & i\jhl*J£ ftflCs. /'J/ J X OfiV$l
ft t/ t J 1 A?^ 0'^ ^ ^ P £o/^/Jf
Dr^uiT Tfinii? /•^/•'O' /)£>[' Lv>f *i -£&$&& '^
fi\f(/frwi£ $At 0 /V<£" 5£ 7 ff}%.& /)^^
•-llsutk? /J££0£, TUA/fi/P /?A^i
hlfi.tt'fl'JiC- 5HiO *"T ujftl Mf 7d /fjut
Oiii O% rt ly \s*>T»>f'd • '' M £<£#?
CO>llhlf/i/7£ [) 0/J HwJ />IUlf/ Jlt\Jg
OM CAVCE. yit 7 3(^.4," up /0tf/^pin

. ...
'
^Wuntbcr shown in parenthesis is
tlic dirforfiicc in Ui'tl from the
r.i.inufsctiirers specif. -ications.
3". 50
tf
5:oO
0.06>
^. S"°



Cos

/94» ^^o 700
M
5^0 ^,£JO 7^io
(-S0>
5^£ 5tfO /jjO
(^7 «/O -730
Voy
^ -if fi-o
ltd -'?D -7 00
(0)

• '

!••= TIIC 2ICO

3 . 3
/8 /6
'••7
lo ID
8 f
/3 i-
•
4
' '<
Loft Rlpji

,,--,. » 	 „
fW7ilrj£ t-fy& '£f^ \
i
i
i
. i
i
/"Jf/vF/e ^/y/s Sr/- |
i
i •;
i '.
: \
i
i
' " .1

in tlsc- "rich" dirncti
"-" = nur.ibor of 't turp..
. iu tlui "jLc.!ii"--oivcctlj

-------