Page 187 of 1413
ENGINE COMPARTMENT HOSE CONNECTIONS:
Bl88l engine:FAST IDLETHERMOVALVE
THERMOSTATHOUSIITGIDLE AIR CONTROLIIAC} VALVE
O'RINGReplace.
BREATHER PIPE
O-RINGReplace.
HEATER HOSES
818C1 engine:
ENGINE OILCOOLER
IAC VALVE
HEATER BYPASSPIPE
FAST IDLETHERMOVALVE
THERMOSTATHOUSING
BREATHER PIPE
HEATEB HOSES
10-3
Page 197 of 1413
Component Locations
lndex
B18Cl ongino:
THROTTLEPOSITION (TP}
SENSOR
MANIFOLD AESOLUTEPRESSURE (MAPI SENSOR
Troubleshooting, page 1 1-52
EVAPPURGE CONTROLSOLEiIOID VALVETroubleshooting,page 11-137
VALVE
INTAKE AIR TEMPERATURE
IIAT) SENSORpage 11-62
THROTTLE CABLEInspection/Adiustment, page 'l 1-1 19
lnstallation, page 1 1-1 19
IOLE AIF CONTROL (IACI VALVETroubleshooting. page 1 1 -82
Troubleshooting,page 1 1-6O
TOP DEAD CENTER/CRANKSHAFTPOSITION/CYLINDER POSITION
{TDC/CKP/CYPI SEI{SORTroubl€shooting. Page 1 1 -56POWER STEERING PRESSURE (PS'I
swtTcHTroubleshooting, page 1 1-93ELECTRICALLOADDETECTORIELD}Troubleshooting,page.1 1-70
IGNITION CONTNOL MODULE OCMI
Troubleshooting, Psge 1'l-66
ENGIT{E COOLANT TEMPERA
{ECT} SEI{SORTroubleshooting, Pag€ 1 1-58
sElrlsoR tKslTroubfeshooting, page 1 1 -7 4
HEATED OXYGEN SENSOR (HO2S}
Troubleshooting, pages 11-46, 47
FAST IDLEInspection, page 1 'l -94
11-4
Page 201 of 1413
ENGINECOOLANT
@ FUEL TAI{K EVAPORATIVE EMISSION (EVAP} VALVE
G) FUEL PULSATION DAMPER
@ AIR CLEANER
@) RESONATOR
@ THREE WAY CATALYTIC CONVEnTER (TWC)
o POS|TIVE CRANKCASE VEITITILAT|ON IPCV) VALVE
@ EVAPOBATIVE EMISSION IEVAP) COI{TROL CANISIER
@ EvApoRATrvE EMrssroN IEVAP) PURGE coNTRoL
SOLENOID VALVE
@ EVAPORATTVE EMISSION (EVAP) PURGE CONTROL
DIAPHRAGM VALVE(iD EVAPORATIVE EMISSION (EVAPI TWO WAY VALVE
|l
U]
HEATED OXYGEI{ SEI{SOF (HO2S}
MANIFOI.D ABSOLUTE PRESSURE (MAP) SEI{SONENGINE COOLANT TEMPERATURE IECT} SENSORINTAKE AIR TEMPERATURE IIAT} SEI'ISORIDLE AIR CONTROL IIAC) VALVEFAST IDLE THERMO VALVEFUEL II{JECTORFUEL FILTERFUEL PRESSURE REGULATONFUEL PUMP IFP)FUEL TAI{K
11-9
Page 203 of 1413
G) FUEL PUI-SATION DAMPER
@ AIR CLEANER(D RESONATOR6 imrlre arR Bypass (tAB) coNTRoL DIAPHRAGM
VALVE(D) IITITP IIN BYPASS {IAB) COTROL SOLENOID VALVE
ds) INTIXT AIR EYPASS TIABI VACUUM TANK
rio'l rnrarg ltn BYPASS (lABl cHEcK vALvE
6 rsnee wav cATALYTtc coNvERTER lrwc)
6 posrnve cRAf{KcAsE vENTILATIoN {Pcv) vALVE
6 evlponlrtve EMtsstot{ tEvAPl coNTBoL cANlsrER
6 evlponltvE EMtssloN {EvAP} PURGE coNTRoL
SOLENOID VALVE6i EVAPORATIV€ EMISSION (EVAPI PURGE CONTROL
DIAPHRAGM VALVE
6o ivlpoalrtve Eutsstof{ IEVAPI rwo wAY vALvE
c) HEATED OXYGEN SENSOR lHO2Sl
€) MANIFOLD ABSOLUTE PRESSURE IMAPI SENSOB
O EI{GINE COOLANT TEMPERATURE {ECT} SENSOR
€) INTAKE AIR TEMPERATURE {IAT) SENSOR
@ KNOCK SENSOR tKSl
@ IDLE alR coNTRoL llAcl vALvE
O FAST IDLE THERMO VALVE
@ FUEL INJECTOR
@ FUEL FILTER
@ FUEL PRESSURE REGULATOR
O) FUEL PUMP (FPI
@) FUEL TANK
@ FUEL TANK EVAPORATIVE EMISSION IEVAPI VALVE
11-11
Page 268 of 1413
System Description
The idle speed ot lhe engine is controlled by the ldle Air Control {lAC) Valve.
The valve changes the amount ot air bypassing into the intake manifold in response to electric current controlled by the
ECM. When the IAC Valve is activated, the valve opens to maintain the proper idle speed.
#l' ----rTo FGM-FIMAINRELAY
VARIOUSSENSORS
IAC VALVE
FASTIDLETHERMOVALVE
INTAKE MAI{IFOLD
(cont'd)
BLK
r
11-79
Page 269 of 1413
ldle Control System
System Description (cont'd)
1 . Atter the engine slarts. the IAC valve opens for a censin time, The amount ot air is increased to raise the idle soeedabout 15O-3OO rom.
2. When the coolant temperature is low, the IAC valve is opened to obtain the proper fast idle speed. The amount ofbypassed air is thus controlled in relation to the engine coolant temperature.
IDI-E SPEEDlrpm)
176
80
ENGINECOOLANT TEMPERATURE
t"Fl(oct
11-80
Page 270 of 1413
1. when the idls speed is out of specification and the Malfunction Indicator Lamp (MlLldoes not blink Diagnostic Trou-
ble Code (DTC) 14, check the tollowing items:. Adiust the idle speed {see page I1-95). Air conditioning signal (see page l1-84). ALT FR signal (see page '11-86)
A/T gea, position signal (see page 11-88)
Erake switch signal (see page 1 1-90)
Starter switch signal (see page 1l-921
PSP switch signal (see page 1 1-93)
Fast idl6 thormo valve (see page l1-94)
Hoses and connsctions
IAC valve and its mounting O-rings
2. lf the above items are normal, substitute a known-good IAC vslv€ and readjust the idle speed (see page 11-95)'
. It the idle speed srill cannot be adjusted to speciJication (and the MIL does not blink code 14) after IAC valve
roplacement, substitute a known-good ECM and recheck. It symptom goes away, replsce the original ECM.
1 1-81
Page 283 of 1413

ldle Control System
Fast ldle Thermo Valve
DEscliptlon
To prevent erratic running when the engine is warming
up, it is n€cessary to raise the idle speed. The fast idle
thermo valve is controlled by a thermowax plunger, When
the engine is cold. the engine coolant su.rounding the
thermowax contracts the plunger, allowing additional air
to be bypassed into the intake manifold so that the en-
gine idlss taster. When the engine reaches operating tem-
peratur€, the valve closss, reducing the amount of air
bypassing into the manifold.
FAST IDLE THERMOVALVE
AIN EYPASS VALVE
Inspaction
NOTE: The tast idle thermo valve is factory adiustsd;
it should not be disassombl€d.
1. Remove the intake air duct from the throttlg body.
2. Stan the engine.
3. Put your finger over ths lower port in throttle body
and make sure that there is 8ir flow with tho engine
cold (engine coolant temperatute below 86oF,
300c).
a lf not,
retest.
leplace the fast idle thermo valvs and
4.
o-Rr{GsReplace
llo kgf.m, 7 lbt.trl
Start the engine. Hold the sngine at 3.0OO rpm with
no load (A/T in I or @ position, M/T in neutral]
until the radiator fan comes on, then let it idl6.
Check thst valve is completely closed. lt not, air suc-
tion can be telt at the lower Don in the throttle body,
a It any suction is felt, the valve is leaking Check
engine coolant level and for air in tho engine
coolant system (see section 1O). ll OK, rsplace
the fast idle thermo valve and rechock.
11-94