Remove the fuel return hose and positive crankcase
ventilation (PCV) hose.
Remove the brake booster vacuum hose, water
bypass hose and vacuum hose.
ERAKE BOOSTERVACUUM HOSE
HOSE
VACUUM HOSE
HOSE
9.
10.
Remove the throttle cable.
Remove the throttle control cable (automatic trans-
mission only).
NOTE:
. Take care not to bend the cable when removing
it. Always replace any kinked cable with a new
one.
. Adjust the throttle cable and throttle control
cable when installing (see section 11 and 14).
THROTTLE CONTROLCABLE
Remove the engine wire harness connectors and
wire harness clamps trom the cylinder head and the
intake manifold.
Four fuel injector connectors
Intake air temperature (lAT) sensor connector
Engine coolant temperature (ECT) sensor con-
necror
TDC/CKP/CYP sensor connector
lgnition coil connector
ECT gauge sending unit connector
Throttle position (TP) sensor connector
Manifold absolute Dressure (MAP) sensor con-
nector
ldle air control (lAC) valve connector
EVAP purge control solenoid valve connector
11.
a
a
a
a
a
a
a
a
a
(cont'dl
ATI'USTING
6-17
ll.Remove the engine wire harness connectors and
wi.e ha.ness clamps from the cylinder head and the
intake manitold.
Four fuel injector connectors
Intake air tempe.ature {lAT) sensor connector
Engine coolant temperature (ECT) sensor con-
nector
TDC/CKP/CYP sensor connector
lgnition coil conn€ctor
ECT gauge sending unit connector
Throttle position (TP) sensor connector
VTEC solenoid valve connector
VTEC Dressure switch connector
Manifold absolute pressure (MAP) sensor con-
nector
ldle air control {lAC) sensor connector
EVAP purge controlsol€noid valvo connector
Intake air bypass {lABl control solenoid valve
conneclor
a
o
a
o
a
a
a
a
a
a
a
a
a
12.
13.
Remove the spsrk plug caps and distributor from
the cylinder head.
Remove the upper radiator hose, heat€r hose and
water bypass hose.
WATER BYPASS
HOSE
6r1.0mm9.8 N.m (1.0 kgt m,1.2 tbtftl
14. Remove the sDlash shield.
Remove the engine ground cable.
Romovo the adjusting bolt and mounting bolts, then
remove the power steering (P/S) pump belt and P/Spump.
. Do not disconnect the P/S hoses.
(cont'dl
15.
6x1.0mm9.8 N.m 11.0 kgl.m,7.2 tbt.ttl
6-57
,l
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
PGM-FIIOLE CONTROLFUEL SUPPLY
INTAKEAIR€MtsstoNCONTROLSELECTRICALLOAODETECTOR
VARIAEIE VALVETIMINC & VALVELIFT ELECTRONICcoNTRO|-SOLENOID
VARIABLE VALVETIMING & VATVEI-IFT ILECTRONICcottTR0tPffESSURE
KNOCKstNsoRFISIGNALFISIGNAT
IOLE AIRc0NTR0r-OTHERIOLECONTROLS
FUELINJECTOR
OTHERFUELSUPPTY
| 1"70s3811.74r 1-76t 1-7611-8211-78| 1-102r 1-97t 1-1 15ll129
Er6t-- -------16l-/-----..Efl-o_,.''\
\.-r-l-t l0 t----i-\t2t I/ --i-\
\-!-/
l22 l/-- j--\t23 l-/--.i-\-t 30 l-,--T-\
\.--r-z
t3r t-/-.--\
\.---l
[|-/----\I 16 t-/ _-i- \
@
@
o@
o@@
oQ)
@a,@@
o@@
@o
o
(JJ
@@@o@
11-3
Troubleshooting
Self-diagnostic Procedures (cont'dl
':818C1 engine
a lf codes other than those listed above are indicated, verifv the code. lf the code indicated is not listed above, replace
rhe ECM.
a The MIL may come on, indicating a system problem when, in fact, there is a poor or intermittent electricalconnection.
First, check the electrical connections, clean or repair connections it necessary.
o The MIL and @ indicator light may light simultaneously when the Diagnostic Trouble Code (DTC) 6, 7 or 17. Check
the PGM-Fl system according to the PGM-Fl system troubleshooting, then recheck the l!! indicator light. ll it lights,
see page 14-5O, 51.
a The MIL does not come on when there is a malfunction in the A/T Fl signal or Electrical Load Detector (ELDI circuits.
However, it will indicate the codes when the Service Check Connector is shorted.
DIAGNOSTIC
TROUBLE
CODE (DTCISYSTEM INDICATEDPsge
oENGINE CONTROL MODULE IECM)11-42
,lHEATED OXYGEN SENSOR IHO25)1 1-46
aMANIFOLD ABSOLUTE PRESSURE {MAP SENSOR)11-52
4CRANKSHAFT POSITION (CKP SENSOR)1 1-56
oENGINE COOLANT TEMPERATURE (ECT SENSOR)11-58
THROTTLE POSITION (TP SENSOR}11-60
ITOP DEAD CENTER POSITION (TDC SENSORI1 1-56
9No. 1 CYLINDER POSITION (CYP SENSOR)1 1-56
10INTAKE AIR TEMPERATURE (IAT SENSOR)11-62
13BAROMETRIC PRESSURE (BARO SENSOR}1|-64
14IDLE AIR CONTROL (IAC VALVE}11-42
tcIGNITION OUTPUT SIGNAL11-66
toFUEL INJECTOR1't-102
17VEHICLE SPEED SENSOR {VSSI11-68
20ELECTRICAT LOAD DETECTOR (ELD)'t 1-70
21VARIABLE VALVE TIMING & VALVE LIFT ELECTRONIC CONTROL SOLENOID
VALVE {VTEC SOLENOID VALVE)'6-36
22VARIABLE VALVE TIMING & VALVE LIFT ELECTRONIC CONTROL PRESSURE
SWITCH (VTEC PRESSURE SWITCHI-6-38
23KNOCK SENSOR {KS}-11-7 4
30A/T FI SIGNAL A11-76
3'rA/T FI SIGNAL B1 1-76
4'lHEATED OXYGEN SENSOR (HO25} HEATER11-47
43FUEL SUPPLY SYSTEM1 1-50
11-36
PGM-FI System
System Description
ENGINE CONTROL MODULE (ECMIOUTPUTS
PGM-Fl System
The PGM-Fl system on this model is a sequential multipon fuel injection system,
Fuol Iniector Timing and Duration
The ECM contains memories tor the basic discharge durations at various engine speeds and manifold pressures. Thebasic discharge duration, after being read out from the memory, is turther modilied by signals sent from vanous sensofsto obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve (lAC Vatve)
When the engine is cold, the A/C compressor is on, the transmission is in gear (A/T only) the brake pedal is depressed,the P/S load is high, or the alternalor is charging, the ECM controls current to the IAC Valve to maintain correct idle soeed.
lgnition Timing Controla The ECM contains mamories for basic ignition timing at various engine speeds and manifold pressures. lgnition timingis also adjusted for engine coolant temperature.a A Knock Control System is also used. when detonation is detected by the knock sensof. the ignition timing is retarded(B18Cl engine).
Other Control Functions
1. Starting Control
When the engine is started. the ECM provides a rich mixture by increasing fuel injector duration.2. Fuel Pump Control
a When the ignition switch is initially turned on, the ECM supplies ground to the PGM-Fl main relay that suppliescurrent to the fuel pump tor two seconds to pressurize the tuel system.a When the engine is running, the ECM supplies gfound to the PGM-Fl main relay that supplies current to the fuel pump.a When the engine is not running and the ignition is on, the ECM cuts ground to the PGM-FI main relav which cutscurrent to the fuel pump.
TDC/CKP/CYP Sensor
MAP Senso.
ECT Sensor
IAT Sensor
TP Sensor
HO2S
vss
BARO Sensor
ELD
Starter Signal
ALT FR Signal
Air Conditioning Signal
A/T Gear Position Signal
Battery Voltage {lcN. 1)
Brake Switch Signal
PSP Switch Signal
Knock Sensor'
VTEC Pressure Switchr
Fuel-lnjectors
PGM-FI Main Relay (Fuel Pump)
MIL
IAC Valve
A/C Compressor Clutch Relay
Radiator Fan Relav
Condenser Fan Relav
ALT
rcM
EVAP Purge Control Solenoid
HO2S Heater
VTEC Solenoid Valve'
IAB Control Solenoid Valve*
lFuet tnjector Timing and Duration]
I Electr..l"ldle Contr;il
Fit'e' contr; Funcrfit
l6tio; Ttntrlg c..trol
tEcM aack-,rp Functiorlsl
': 818C 1 €ngine
11-40
3. Fuel Cut-oft Control
a During deceleration with the throttle valve closed, current to the {uel injectors is cut otJ to improve fuel economy
at speeds over tollowing rpm:
. 8188l engine: 91O tpm (Canada model: 1,O50 rpm)
. 818C1 engine: 95O tpm (Canada model: l,O5O rpm)
a Fuel cut-olf action also takes place when engine speed exceeds, 7,O0O rpm {81 8B1 engine), 8,1O0 rpm (B 18Cl
engine), regardless oI the position of the throttle valve, to protect the engine from ovet-revving.
A/C Compressor Clutch Relay
When the ECM receives a domand for cooling trom the air conditioning system, it del8ys the compressor from being
enetgized, and enriches the mixture to assure smooth transition to the A/C mode.
Evaporative Emission (EVAP) Purge Control Solenoid Valve
When the engine coolant tempersture is below 163oF {73"C), the ECM supplies a ground to the EVAP pu.ge control
solenoid valve which cuts vacuum to the EVAP purge control diaphragm valve.
Intake Air Bypsss (lAB) Control Sol€noid Valve
When the engine rpm is below 5,750 rpm, the IAB control solenoid valve is activated by a signal from the ECM,
intske air flows through the long intake path, then high torque is delivered. At spaeds highe. than 5,750 rpm, the
solenoid valve is deactivated by the ECM, and intake air flows through the short intake path in order to reduce the
resistance in airflow.
ECM fail-safe/bEck-up Functions
1. Fail-sate Function
When an abnormality occurs in a signal from a sensor, the ECM ignores that signal and assumes a pre-progtammed
value tor that sensor that allows the engine to continue to run.
Back-uD Function
When an abnormalitv occurs in the ECM itself, the fuel iniectors are controlled by a back-up citcuit independent of
the system in order to permit minimal driving.
Self-diagnosis Function IMaltunction Indicator Lamp {MlL)1
Wh6n an abnormality occurs in a signal from a sensor, the ECM supplies ground for the MIL and stores the code
in erasable memory. When the ignition is initially turned on, the ECM supplies ground tor the MIL tor two seconds
to check the MIL bulb condition.
Two Trio Detection Method
To prevent tals€ indications, th€ Two Trip Dstection Method is used for the HO2S and fuel metering-related self-
diagnostic tunctions. When an abnormslity occurs, the ECM stores it in its memo.y. Wh€n the ssme sbnormality
recurs alter the ignition switch is turned OFF and ON ag8in, the ECM informs the driver by lighting the MlL.
However, to ease troubleshooting, this function is canc€ll€d when you short the service check connector. The MIL
will then blink immedistelv when an abnormality occurs.
4.
6.
2
4.
11-41
Fuel Supply System
System Troubleshooting Guide
NOTE: Across each row in the chart, the sub-systems that could be sources of a symptom ara tanked in tho order they
should be inspected starting with O. Find the symptom in the left column, read across to the most liksly source, then
refer to the page listed at the top of that column. lf inspection shows the system is OK, try the next most liksly system
@, etc.
PAGE
SYI\4 PTOM
FUEL
LINES
FUEL
INJECTOR
FUEL
PRESSURE
REGULATOR
FUEL
FILTER
FUEL
PUMP
PGM-FI
MAIN
RELAY
CONTAM'
INATEO
FUEI
11-9811-1021 1,106l1-toa11-109t'l'nl
ENGINE WON'T START@o@
DIFFICULT TO START
ENGINE WHEN COLD OR HOTo\4
ROUGH IDLEo@
POOR PER.
FORMANCE
MISFIRE OR
ROUGH
RUNNINGo@@
FAILS
EMtSSION@o
LOSS OF
POWER@@o
FREOUENT
STALLING
WHILE
WARMING
UPo
AFTER
WARMING
UPo
11-97