Page 312 of 1413
Intake Air Bypass (lABl Control System tBl8C1 enginel
Osscription
Two air intake paths are provided in the intake manifold to allow the selection of the intak€ path most favc
given engine speed.
Satisfactory power peformanc€ is achieved by closing and opening the intake air bypass (lAB) control valve!
que at low RPM is acheived when the valves are closed, whereas high power at high RPM is achieved by when
8re oDeneo.
IAB CONTROLVALVES
To PGM-FIMAIN RELi
IABCHECK VALVE
t favorabl€ for a
vslves. High tor-
when the valves
RELAY
(cont'dl
11-123
Page 313 of 1413
Intake
Intake
Air
Air
System
Bypass (lAB) ControlSystem tBl8C1 enginel (cont'dl
Troublcahooting
VACUUII PUMP/GAUG€A973X-041-XXXXX
fromwiro haanasid€
PI{K/BLU I-I
YEI/aLK l+l
tA8 COI{TROLDIAPHRAGM
Insp€ction of IAB Conltol Sytt.m
Start engino and allow to idle.
R€move # 13 vacuum hose tromthe IAB control diaph.agm andconnect vacuum gauge to thehose.
R€move # 12 vacuum hose fromth€ IAB vacuum tank, then checktor vaccum at the IAB vacuumtank.
Rcplir lh. block.g. otvacuufi laak boiwaaotha IAB vacuum tanklnd th. intlk m!ni-fold.
Disconnect the 2P conn€ctor lromthe IAB control solenoid valve.
Measure voltage betweenYEL/BLK (+l torminal andPNK/8LU l-) terminsl.
ls thoro battery voltage?
Measure voltage b€twee nBLK^|/EL (+) torminal and bodyground.
IAB CONTBOLSOLENOID VALVE
Page 314 of 1413

(From page 1 1-124)
Raise engine speed to above6,000 rpm.
Disconnect the 2P connector tromthe IAB control solenoid valve.
Turn the ignition switch OFF.
Check for continuity to ground onthe PNK/BLU wire.
Ropair short to g.ound
at PNK/BLU wiro bo-two6n ECM {A17) andtho 2P connector.
ls there continuity to ground?
Substituto a known-good ECMand racheck. It symptom goos
swsy, roplace tho original ECM.
{From pago 1 1-124}
Repsir op6n in YEL/BLKwiro botwoon tho 2Pconnector and FGM-FImain relaY.
ls there battery voltage?
Turn the ignition swirch OFF.
Connect lhe test harness betweenthe ECM and connectors lseepage 11-37).
Turn the ignition switch ON andconnect a lumper wke betweenECM (A17) terminal and ECM
{A26) terminal.
Ropaiiopon inP K/BLUwiao botwoen ECM
lAl7l and tho 2P con-nectot.
Ooes the solenoid valve clickwhen the jumper is con-nected?
Sub3titute a known-good ECMand rechock. lf symptom/indica-tion goos away, r6place tho origi-nal ECM.
Check lor vacuum at #'l3 vacu-um hose.
IAB control syst6m is OK.
11-125
Page 315 of 1413
a
Intake Air System
Intake Air Bypass (lABl Control Valve IB18C1 enginel
Trlting
GAUTIOI{; Do not rdlust lho IAB control valvo tull-close screw. lt is prosot at th. t.ctoty.
1. Chsck the IAB control valve shsft for binding or sticking.
2. Check th6 IAB control valve for smooth movement.
3. With the engine at idle, check that @ot the IAB control valve is in close contact with the stoppsr when vacuum
hose is disconnected.
With th€ ongine at idl6, check that @of the IAB control valve is in close contact with the full-closo acrew whsn
the vacuum hose is connectad.
a lf 8ny fault is lound, clean the linkage and shatts with carburetor claaner'
- lf the oroblam still exists after cleaning, disassemble the intake manifold and check the IAB valvE body sss8mbly.
11-126
Page 319 of 1413

Emission Control System
SystemDescription
The emission control system includes a Three Way Cata-
lytic Convener (TWC), Positive Crankcase Ventilation(PCV) system and Evaporstive Emission {EVAP) Contfol
syst€m. The emission control system is designed to meet
federsl and stats emission standards.
Tailpipe Emission
Inspection
f!fifil oo nor amoro ou]rng rnr! Foacqurr. ^!op
any open flame away from yout wotk atca.
Start the engine. Hold the engine at 3,OOO rpm with
no load (A/T in @ or@ position, M/T in neutral) until
the radiator fan comes on, then let it idle,
Connect a tachometer.
Check and adiust the idle speed, if necessary (sss
page 1 1-95).
Warm up and calibrate the CO meter according to
the meter manutacturer's inst.uctions.
Check idle CO with the headlights, hester blower,
rear window defogger, cooling fan, and air condition-
er otf.
NOTE: (Canada) Pull the parking br8ke lever up.
Stan the engine, then check that the headlights are
off.
CO meter should indicate 0.1 maximum.
11-130
Page 327 of 1413

(From page 1 1-137)
lTo page 1 1-'l39)
Start the engine. Hold the engineat 3,OOO rom with no load lA/T in
E orE position, M/T in neutrsl)unlil lhe radiator tan comes on.then let it idle.
Check lor vacuum at # 7 vacuumhose alter starting the engine.
Oisconnect the 2P connoctor fromthe EVAP purge control solenoid
Intpoct vacuum hoaarcuting.It OK, reolrco tr|c EVAP
Purge contlol lolanoid
ls there manifold vacuum?
Inrpoct for a short i|t RED wire bo-lwoen ECM {A2Ol and th6 con-noclor.ll wiro la OK, substituto a known-good ECM 6nd .echock. lf symp-tom goes away, loplace tho origi-nal ECM.
Ropair opon in YEL/BLKwirc b.tw..n EVAPpurgo control rolanoidvrlvo and th. xiM-Flmlin r6lay.
ls there baftery voltage?
Inspoct RED wirc for 6n opon totrody g.ound botween ECM lA20)and th6 conn6ctor.It wir. b OK, substiluto a known-good ECM and rochock, It sym-ptom 9o6s away, roplaco thooriginal ECM,
Emission Gontrol System
Evaporative Emission (EVAP) Gontrols (cont'd)
{From page 11-137}
11-138
Page 334 of 1413

Adjustment
NOTE:
a To check the clutch interlock switch and clutch
switch, see seclion 23.
a The clutch is selt-adjusting to compensate for wear.
CAUTION: It there is no clearanco between the mastel
cylinder piston and push lod. the releaso boaring is held
againsl the diaphragm spring, which can result in clutch
slippage 01 othel clutch problems.
Loosen locknut A, and back otf the clutch switch
{or adjusting bolt) until it no longer touches the clutch
pedal.
Loosen locknut C, and turn the push rod in or out
to get the specified stroke (@) and height (O) at the
clutch pedal.
Tighten locknut C.
Turn the clutch switch (or adjusting bolt) until it con-
tacts the clutch pedal.
Turn the clutch switch (or adjusting bolt) in 3/4 to
1 full turn further.
Tighten locknur A.
7. Loosen locknut B and the clutch interlock switch.
8. Measure the clearance between the tloor board and
clutch pedal with the clutch pedal tully depressed.
9. Release the clutch pedal 15-20 mm {O.59-O.79
in) from the fully depressed position and hold it there.
Adiust the position of the clutch interlock switch so
that the engine will start with the clutch pedal in this
oosition.
1 0. Turn clutch interlock switch 3/4 to 1 tull turn funher.
11. Tighten locknut B.
LOCKNUT B9.8 N.m (1.0 kgf.m, 7 lbf.ftl
CLUTCH INTERLOCKswtrcH
6.
1.
2.
ASSIST SPRING
-6ll
LOCKNUT Cl3 N.m l'l.3 kgf.m, 9
CLUTCH SWITCH{or AOJUSTING BOLTI
LOCKNUT A9.8 {N.ml (1.0 kgl.m, 7 lbt.ftl
(STROKE at PEDALI: 130-140 mm 15.12-5.51 in){TOTAL CLUTCH PEDAL FREE PLAY): 12-21 mm 10.47-0.83 inl including tho p.dal play I -lO mm 10.04-0.39 inl{CLUTCH PEDAL HEIGHTI: 164 mm (6.46 in} to tho lloot{CLUTCH PEDAL DISENGAGEMENT HEIGHTI: 83 mm 13.27 inl minimum to tho lloo.
PUSH ROD
CLUTCH MASTER CYLINDER
Clutch Pedalctutch Pedat I
[-],ll'"-"" f
| :;i:'":fff*tr#:?iff:".,*::,::". | .#::J:::
sb'' ' '""
| |
| "orr,O", It there is no clearanco between the master | ,. aoo""n locknut B and the clutch intertoct switcl. | |cylinder piston and push lod. the releaso boaring is held | | Iagainst the diaphragm spring, which can result in clutch | 8. Measure tne clearance between the floor board and I Islippage 01 othel clutch problems.
I
clutch pedal with the clutch pedal tully deeressed.
I I1. Loosen locknut A, and back otf the clutch switch | 9. Release the clutch pedal 15-2O mm (O.59-O.79 I I
{or adiusting boltl until it no longer touches the clutch I int trom ttre fully depressed position and hold it there. I I
, ::":"" rocknut c, and rurn the push rod in or out | iliiiliffi:l1l:J"'1"-:H"l:tJ:i"i#fT: I I
. il*:*j':"'-(@)andheisht(olatthe
|
,:.;:,nterrockswitch3/4torrurrturnturtner.
I tf
,
::
***r**''
.,".,u"**;
|
'-"'"'';*1,,0*.,.-,.,*,
I I
Page 339 of 1413

InspectionReplacement
Flywheel, Flywheel Bearing
Inspect the ring gear teeth for wear and damage.
Inspect the clutch disc mating surface on the
flywheel fo. wear, cracks, and burning.
Measure the flywheel runout using a dial indicator
through at least two full tu.ns. Push against the
Ilywheel each time you turn it to take up the crank-
shaft thrust washe. clearance.
NOTE; The runout can be measu.ed with engine in-
stalled.
Standard (ttlervl: O.O5 mm (O.002 inl Max.
Service Limit: 0.15 mm 10.006 inl
RING GEABFLYWHEEL
DIAL II{DICATOR
It the runout is more than the service limit, leplace
the flvwheel.
Turn the inner race of the flywheel bearing with your
finger. The bearing should turn smoothly and quiet-
ly, Check that the bearing outer race fits tightly in
the flvwheel.
FLYWHEELBEARING
It the race does not turn smoothly, quietly, or fit
tight in the flywheel, replace the flywheel bearing.
Install the special tool.
Remov€ the flywhe€l mounting bolts in a criascross
pattern in several steps 8s shown, then remove the
tlywheel.
MOUI{TII{G BOLTS
3. Remov€ the flywheel bsaring from th€ tlywheel.
(cont'd)
FLYWHEEL
12-9