1998 ACURA INTEGRA ignition timing

Troubleshooting
DataDescriotionOperating ValueFreeze Data
HO25
Feedback
Loop Status
Loop status is indicated as "open" or "closed".
Closed: Based on the H02S output, the ECM deter-
mines the airlfuel ratio and controis the amount of
iniected fuel.
Open: lgnoring HO2S output, the ECM refers to sig-
nals from the TP, MAP, and ECT sensors to control
the amount of iniected fuel.
Al idle speed: closed
YES
Short Term
Fuel Trim
The airlfuel ratio correclion coeificient lor correcting
the amount ol iniected fuel when HO2S feedback is in
the closed loop status. When the signal from the
HO2S is weak, short term fuel trim gets highef. and
the ECM increases the amount of injected fuel The
airlfuel ratio gradually gets richer, causing a higher
HO2S output.
Consequentlv, the short term fuel trim is lowered, and
the ECM reduces the amount of injected tuel. This
cycle keeps the airlfuel ratio close to the stoichiomeric
ratio when in closed loop status.
-30o/" - + 41%
YES
Term
Trim
Long
F uel
Long term fuel trim in computed trom short term fuel
trim and indicates changes occurring in the fuel sup-
ply system over a long period.
lf long term fuel trim is higher than 1.00, the amou nt
of injected fuel must be increased. ll it is lower than
1.00, the amount of iniected fuel must be reduced
-14% - + 2Oo/"
YES
lntake Air
Temperature(rAT)
The IAT sensor converts intake air temperature into
voltage and signals the ECM. When intake air temper-
ature is low, the internal resistance of the sensor
increases, and the voltage signal is higher.
With cold engine:
Same as ambient temPer-
ature and ECTYES
Throttle
Position
Based on the accelerator pedal position. the opening
anole of the throttle valve is indicated.
Ar idle: Approx. 107o
At full throttle: Approx.
90%
YES
lgnition
Timing
The ignition advance angle is set by the ECM. The
EClvl matches ignition timing to the driving condi-
tio ns.
At idle speed: 16 t 2'
BTDC with the SCS ser-
vice connector connected.
NO
Calculated
Load Value
(CLV)
CLV is the engine load calculated from the MAP data.At idle speedi
15 - 35%
At 2,500 rpm with no load:
12 - 30./.
YES
-38

PGM-FI System
System Description
ENGINE CONTROL MODULE (ECM)OUTPUTS
*1: USA*2: 818C1 engine*3: A,/T*4: 818C1, 818C5 engines
PGM-FI Sy3tem
The PGM-Fl system on this model is a sequential multiport fuel injection system.
Fuel lniector Timing and Duration
The ECM contains memories for the basic discharge durations at various engine speeds and manifold pressures. The
basic discharge duration, after being read out from the memory. is further modified by signals sent from various sensors
to obtain the final discharge duration.
ldle Air Control
ldle Ai. Control Valve (lAC Valve)
When the engine is cold, the Ay'C compressor is on. the transmission is in gear (Ay'T only)the brake pedal is depressed, the
P/S load is high, or the alternator is charging, the ECM controls current to the IAC Valve to maintain correct idle speed.
lgnition Timing Control
. The ECM contains memories for basic ignition timing atvarious engine speeds and manifold pressures, lgnitiontiming
is also adjusted for engine coolant temperature.
. AKnockControl System isadoptedwhich sets the ideal ignition timing for the octane n um ber of gasoline used*r,
Other Control Functions
L Starting Control
When the engine is started, the ECM provides a rich mi{ure by increasing fuel injector duration.
2. Fuel PumD Control
. When the ignition switch is initially turned on, the ECM supplies ground to the PGM-FI main relay that supplies
current to the fuel pump for two seconds to pressurize the fuel system.
. When the engine is running, the ECM supplies ground to the PGM-FI main relay that supplies current to the fuel
DUmO.
. When the engine is not running and the ignition is on. the ECM cuts ground to the PGM-FI main relay which cuts
current to the fuel oumo.
INPUTS
TDc/CKP/CYP Sensor
CKF Sensor
MAP Sensor
ECT Sensor
IAT Sensor
TP Sensor
HO2S
VSS
BARO Sensor
ELD*1
Starter Signal
ALT FR Signal
Air Conditioning Signal
A,/T Gear Position Signal*3
Battery Voltage (lGN.1)
Brake Switch Signal
PSP Switch Signal*'
Knock Sensor*1
VTEC Pressure Switch*4
Fuel Tank Prssure Sensor
Fuel InjectorTiming and Duration
Electronic ldle Control
Other Control Functions
lgnition Timing Control
ECM Back-uD Functions
Fuel-lnjectors
PGM-Fl Main Relay (Fuel Pump)
MIL
IAC Valve
A,/C Compressor Clutch Relay
Radiator Fan Belay*1
Condenser Fan Relay
ALT*1
rcM
EVAP Purge Control Solenoid
Valve
H02S Heater
VTEC Solenoid Valve*'
IAB Control Solenoid Valve*,
EVAP Bypass Solenoid Valve
EVAP Control Canister Vent
Shut Valve
11-48

t@
tFffi6l
F136il
l-P1362l
Fi3BTl
tFE82-l
Crankshaft Position/Top Dead Center/Cylinder Position (CKP/TDC/CYPI Sensor
The scan tool indicates Diagnostic Trouble Code {DTC) P0335: A malfunction in the Crankshaft Position (CKP)
sensor circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) P0336: A range/performance problem in the CrankshaftPosition (CKP) sensor circuit.
The scan tool indicates Djagnostic Trouble Code (DTC) Pl361: Intermittent interruption in the Top Dead Center(TDC) sensor circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) P1362: No signal in the Top Dead Center (TDC) sensorcircuit.
The scan tool indicates Diagnostic Trouble Code (DTC) P1381: Intermittent interruption in the Cylinder Position(CYP) sensor circuit.
The scan tool indicates Diagnostic Trouble Code (DTC) P]382: No signal in the Cylinder Position (CYP) sensorcircuit.
D€scription
The CKP Sensor determines timing for fuel injection and ignition of each cylinder and also detects engine speed. The TDCSensor determines ignition timing at stan-up (cranking) and when crank angle is abnormal. The Cyp Sensor detects theposition of No. 1 cylinder for sequential fuel injection to each cylinder.
NOTE: ll DTC P1359 is stored at the same time as DTC P0335, P0336, Pl361, P1362, P1381 and/or P1382. troubleshoot DTCP1359 first, then troubleshoot those DTCS.
Problcm va.itic.lion:'1. Do the ECM Reset Procedure.2. Stan the engine.
- Th. MIL ha3 bacn r.oort.d on.- olc P0335, P0336, P1361.P1362, P1381 and/o. P1382 erottorad.
Intormittcnt tailurc, rystem is OKat this lima. Checl tor poor con-naclions or loose wire3 at C109{CKP/lDC/CYP Scn30rl rnd €CM.
ls DTC P0335, P0336, P1361, P1362.P1381 and/or P'l382 indicared?
Chcck for .n open in thc TDC/CYP ,.n3or:L Turn the ignition switch OFF.2. Disconnect the CKP/TDC/CYP
3, Measure aesistance betweenthe terminals oI the indicatedsensor {see table).
Rcplaca tho distributor hou3ingscnsor {soa soction 231,ls rhere 0.5 - 1.0 kO?
TOC P (GRN}
Termanal side of male terminals
CYP P {YELI
CYPM IBLK)
SENSOnoTcSENSORTEEMINALECMTEflMINALCOLOR
CKPP0335c2BLU
P0336c12BLU/YEL {WHTI
TDCP13613G8N
P13627c13WHT/8LU {BEO)
CYPP13814c4YEI
P1382ac14WHT (BLK)
I ): ENGINE WIRE HARNESS SIDE
(To page 11-84)
-83

ldle Speed Setting
IDLEADJUSTINGSCREW
7.
6.Turn the ignition switch OFF.
Reconnect the 2P connectors to the IAC valve and
the EVAP purge control solenoid valve, then do the
ECM reset procedures.
Restart and idle the engine with no-load conditions
for one minute, then check the idle speed.
NOTE: (Canada) Pullthe parking brake lever up.
Start the engine, then check that the headlights are off.
ldle speed should be;
Bl88l €ngine:
Mfi750 i 50 rpm
A/T750150 rpm (in Park or neutral)
818C1 engine:750 i 50 rpm
818C5 engine: 800 i 50 rpm
NOTE: 81881, Bl8Cl engines - It the idle speed
increases to *1rpm, this means the EVAP system ispurging the canister. To stop the purging termporarily.
raise the engine speed above 1,000 rpm with the
accelerator pedal, then slowly release the pedal.
*1: 81881 engine
M/T: 820 i 50 rpm
Ay'T: 840 t 50 rpm
818Cl engine
850 I 50 rpm
(cont'd)
Inspection/Adiustmont
NOTE:
. When setting the idle speed, checkthe following items:- The MIL has not been reported on.- lgnition timing
Spark plugs- Air cleaner- PCV system
. (Canada) Pull the parking brake lever up. Start the
engine, then check that the headlights are off.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on, then let it idle,
Connect a tachometer.
Disconnect the 2P connectors from the ldle Air
Control (lAC) valve and the EVAP purge control
solenoid valve.
2.
5.
if the engine stalls, restan the engine with the accel
erator pedal slightly depressed. Stabilize the rpm at
1,000, then slowly release the pedal until the engine
idles.
Check idling in no-load conditions: headlights, blower
fan, rear defogger, radiator fan, and air conditioner
are not ope€tlng.
ldlo speed should be;
B188l engine:
Mlf480 :l 50 rpm
A/T480 i 50 rpm (in Park or neutral)
B18C1 engine: /t80 t 50 rpm
818C5 sngine:550 t 50 rpm
lf necessary, adjust the idle speed, by turning theidle adjusting screw.
After adjusting the idle speed, recheck the ignition
timing {see section 23). lf it is out of spec, go back
to steo 4.

Terminal NumberSignalDescriptionMaasuring Conditlons/Tarminal Voliage
424ACCLAir conditioning (Ay'C) clutch relay
control
With A,/C comDressor ON: 0 V
With Ay'C compressor OFF: Battery voltage
A25tG1Power supply systemWith ignition switch ON (ll)r 12 V
426LG1Ground
B1Not used
82BAROS SBarometric pressure sensor signal
input
With ignition switch ON (ll) and depending on
barometric pressure: Approx. 3 V
B3ECTEngine coolant temperature sen-
sor signal input
With ignition switch ON (ll) and depending on
engine coolant tem perature: Approx. 0.1 - 4.8 V
B4TPSThrottle position sensor signal
input
With ignition switch ON (ll) 8nd throttle fully
open: 4.14 - 4.82 V
With ignition switch ON (ll) and throttle fully
closed: 0.44 - 0.56 V
B5VSSVehicle speed sensor signal inputWith ignition switch ON (ll) and front wheels
rotating; Pulsing signal
B6AFSBUpshifvdownshift comparative
signal output
With engine idling: 0 V
At uDshift or downshift: 5 V for an instant
B7AFSAUpshifvdownshift com parative
srgnal output
With engine idling: 0 V
At upshift or downshift: 5 V for an instant
B8NCSGCountershaft speed sensor signal
ground
Always: 0 V
B9NCCountershaft speed sensor signal
Input
Depending on vehicle speed: Pulsing signal
When vehicle is stopped:0 V
B10NMMainshaft speed sensor signal
input
Depending on vehicle speed: Pulsing signal
When vehicle is stoDoed: 0 V
811Not used
812STOP SWBrake switch signal inputWith ignition switch ON {ll) and b.ake pedal
depressed: Battery voltage
With ignition switch ON (lll and brake pedal
released:0 V
813Not used
814scsTiming adjustment
service check signal
With ignition switch ON (ll) and service check
connector oDen:5 V
With ignition switch ON (ll) and service check
connector connected with special tool: 0 V
815Not used
816Not used
817NMSGMainshaft speed sensor signalgroundAlways: 0 V
818Not used
819FASShift acknowledge inputWith engine idling: 5 V
At upshift or downshift: 0 V for an instant
820VBEF+5 V referenceWith ignition switch ON {lll: Approx. 5 V
82'lNot used
Not used
14-49

lgnition System
1. Inspect the electrodes and ceramic insulator for:
Spark Plug lnspection
. lmproper gap. Oil-fouling. Carbon deposits. Cracked centerelectrode insulatorDamagedgaskei
Burned or worn electrodes may be caused by:
. Advanced ignition timing. Loose spark plug
. Plug heat range too low. Insufficient cooling
Fouled plugs may be caused bY:. Retarded ignition liming. Oil in combustion chamber. Incorrect spark plug gap
. Plug heat range too high. Excessive rdling'low speed running
. Clogged air cleaner element. Deteriorated ignition coil or ignition wires
81881, 818C5 engine:
. Adjust the gap wjth a suitable gapping tool, and
replace the plug if the center electrode is rounded
as shown below.
Electrode Gap:
Standard 'l .1 ; r mm {0.043 ; ooa in)
E.
23-98
3.818C1 engine:
a Do not adjust the gap ol a platinum tip plug;
replace the spark plug it the center electrode is
rounded or if the gap is not within the specifi-
cattons.
Electrode Gap:
Standard I t.s-3., mm (0.051-3.oo4in)
5.
PLATINUM TIP
NOTE: Use onlv the spark plugs listed below
Spark plug
Bl88l engine:
NGK I ZFR5F-11
DENSO I KJ 16CR-111
818C1 engine:
NGK PFR6G-13
DENSO I PK2OPR-113
818C5 engine:
NGK PFR6G-I1
DENSO PK2OPR-111
Apply a small quantity ot anti-seize compound to the
plug threads belore installing the plugs.
Screw the plugs into the cylinder head tinger tight,
then torque them to 18 N.m (1 .8 kgf.m, 13lbf.ft).