Page 435 of 2189

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected. the MIL will blink during the time of its occurrence, and DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through P0304 will be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC. troubleshoot those DTCS first, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304
Page 436 of 2189

I
Misfire Detected in One Cylinder
P0301 | The scan tool indicates Diagnostic Trouble Code (DTC) P0301: Cylinder 1 misfire detected.
[F03O2l 16"""untool indicates Diagnostic Trouble code (DTc) P0302: Cylinder2 misfire detected.
[FO3Ofl 16" ".un toot indicates Diagnostic Troubte Code (DTC) P0303; Cylinder 3 misfire detected.
I P0304 I ths..rr tool indicates Diagnostic Trouble Code (DTC) PO3O4: Cylinder 4 misfire detected.
D€scription
lMisfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor
which is attached to the crankshaft,
lf misfiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurrence, and DTC
PO3O1, P0302, PO3O3 or P0304 will be stored. Then, after the misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cyclss, the MIL will come on, and DTC
P0301, P0302, P0303 or P0304 will be stored.
NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC, troubleshoot those DTCS first, then
recheck for the misfire DTC.
PO106*1, P0107, P0108. P1128*3'*5, P1129*3'*5: MAP sensor
P0131, P0132: HO2S
P0171, P0172iFuel suppiy system
P0335, P0336: CKF sensor
P0401. P1491, P1498: EGR system
P0441: EVAP system Insufficient purge flow*6
Pl359. P1361. Pl362: TDC sensor
P1381. Pl382: CYP sensor*o: '96 models*6: '96 D16Y5 engine,'96 D16Y/ engine,'96 D16Y8 engine {sedan),'97 D16Y5 engine,'97 D16\4, engine (coupe: KA,
KC models, sedan KA. KC, KL (DX) models, hatchback:all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
. Fuel injector clogging, fuel leakage, air leakage
. Fuel injector circuit open or shorted
. Spark plug carbon deposits, fouling, malfunction
. lgnition wires open. leaking
. Distributor malfunction
. ComDression low
. Valve clearance out of spec
. VTEC system malfunction (D16Y5, D16Y8. 81642 engine)
. HO2S
. HO2S circuit
(cont'd)
11-167
r'a
Page 459 of 2189
ldle Control System
System Description
The idle speed ot the engine is controlled by the ldle Air Control (lAC) Valve.The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled bv theECM/PCM. When the IAC Valve is activated, the valve opens lo maintain the proper idle speed.
D16Y5, D16Y8, Br6A2 engine (M/T):
(ROTARYItac vat-vEEI{GINEcooLAI{T
VARIOUSsEI{SORS
VARIOUSSENSORS
INTAKE MANIFOTDDl6Ys {CVTl, D16Y8 engine lA/T):
D16Y7 engine:
{ROTABY)
;iy--, - ---
INTAKEMANIFOLD
11-190
Page 462 of 2189
I
L
1D16Y5, D16Y8 engine with M/T 81642 engine)I
D16Y7 engine:
{From page 11-192)
Check the IAC valve:Disconnect the 3P connector from
the IAC valve.
Check the IAC valve:Disconnect the 2P connectorfrom the IAC valve.
Does the engine speed drop or
the engine stall?
Adiust the {base} idle speod (see
page 11-220 - 2231.It it's impos-
aible, clean the ports in lhe throt'
tle bodv,
(From page 11-192i
Check Ior vacuum leaks:1. Turn the ignition switch OFF.2. Remove the intake air ductfrom the throttle body.
3. Start the engine and let it idle.
4. Put your finger on the lowerpon in the th.ottle body.
Ch€ck tor vecuum loaks, m.kesure the throttle valve is com_pletaly closed, end repair as nec-Does the engine speed droP?
Adiust the idle speed (see page
11-220 - 2231. lf it's impossible,
reolace the IAC velve.UPPERPORT
1 1-1 93
Page 490 of 2189

t
t
I
'96.'97 D16Y5 engine with CVT,'96 - 00 D16Y8 ongins
with A/T and'96 - 00 Dl6Y7 €ngine
Adiust the idle speed using a Honda PGM Tester if pos-
sible. lf not, use the following procedure:
NOTEI
. Leave the IAC valve connected
. Betore setting the idle speed. check the following
items:- The MIL has not been reported on'
- lgnition timing
- Spark Plugs- Air cleaner- PCV system
1. Connect a tachometer.
2. Start the engine. Hold the engine at 3,000 rpm wirh
no load (in Park or neutral) until the radiator fan
comes on, then let it idle.
3. Check the idle speed with no-load conditions: head-
iights, blower fan, rear defogger, radiator fan, and
air conditioner are not operatlng
ldl€ spoed should be:
USA:
D16Y5 engine with CVT, D16Y7 engine with A/T'
Dl6YB engine with A/T:
700 :r 50 rpm (in E or El Positionl
D16Y7 engine with M/T:
670 i 50 rpm
Canada:
Dl6Y8 sngin€, Dl6Y7 engins:
M/T750 t 50 rpm
NT750 1 50 rpm (in E or El Position)
Adjust the idle speed, if necessary, by removing the
cap and turning the idle adiusting screw 1/2-turn
clockwise or counterclockwise
D16Y5, D16Y8 engine:
IDLEADJUSTING
Dl6f, ongine:
NOTE: When you remove the ACL housing, do not
disconnect the IAT sensor connector
After turning the idle adjusting scrow 1/2-turn'
check the idle speed again. lf it is out of spec, turn
the idle adjusting screw 1/2-turn agaan'
NOTE: Do not turn the idle adjusting screw more
than 1/2-turn without checking the idle speed'
ldle the engine for one minute with heater fan
switch at Hl and air conditioner on, then check the
idle speed.
ldle speed should be:
M/T810150 rpm
A/T. CvT810 t 50 rpm (in El or E Position)
NOTE:
. Do not turn the idle adjusting screw when the air
conditioner is on.
. lf the idle speed is not within specification. see
Symptom Chart on page 11-84 (cont'd)
11-221
Page 501 of 2189
Fuel Supply System
Fuel Injectors
Replacement
@ Do not smoke when working on the tuel systgm, Keep gp6n flames away from your work area
'f. Relieve the fuel pressure (see pages 11-230,231J.
2. Disconnect the connectors from thefuel injectors (D16Y7 engine: Remove the air cleaner).
3. Disconnect the vacuum hoses from thefuel pressure regulator. Placeashoptowel overthefuel return hose, then dis-connect it from the fuel pressure regulator. Disconnect the vacuum hoses and 2P connector from the EVAp purgecontrol solenoid valve.
4. Remove the retainer nuts on the fuel rail.
5. Disconnect the fuel rail.
6. Removethefuel injectors from the intake manifold.
D16Y5, D16Y8 engine:
NOTE: lllustration shows D16Y8 engine.
D16Y5 engine is similar.
12 N.m11.2 kgl.m,8.7 rbt.ft)
12 N.m11.2 lgl.m,8.7 rbt.ftl
.q
wE4
Y
Ve
ffi}Yg
E
O.RINGReplace.
CUSHIONRINGReplace.
O.RINGReplace.
cusl{toNRINGReplace.
SEALRINGReplace.
ffi
E
EV
R
w
t
YEVAPPURGE CONTNOLSOLENOID VALVE
FUEL
11-232
Page 512 of 2189
Intake Air System
\JSystem DescriPtion
The system supp|ies air for a|| engine needs' |t consists of the intake air pipe' Air C|eaner (ACL}, intake air duct, Thrott|e
Body (TB), ldle Air control (lAc) valve and intake manifold. A resonator in the intake air pipe provides additional silencing
as air is drawn into the system.
D16Y5, D16Y8, 816A2 engine {M/Tl
YEL/ - From PGM-FIaLK - MA|N RELAY
BLK/BLU
-- ORN
INTAKEAIRDUCT
IROTARYIIAC VALVE
Iaru
ENGINECOOLANT
BLK/
INTAKEAIR DUCT
I
D16Y5 engine (CVT), D16Y8 engine (A/T)' f'ttlxr ,tla"tpoto
D16Y7 engine:
{ROTARY)IAC VALVE
VARIOUSSENSORS
INTAKEAIRPIPE
tr
RESONATOR
!r,
IAC VALVE
BLK
11-243
Page 514 of 2189
\J
816A2 engine:
DEFLECTION10-12mmBla- 112inl
CABLE ADJUSTINGBRACKET NUT
t
lf deflection is not within specs' loosen the locknut'
turn the adjusting nut untilthe deflection is as speci-
fied, then retighten the locknut.
With the cable properly adiusted, check the thronle
valve to be sure it opens fully when you push the
accelerator pedal to the floor. Also check the throt-
tle valve to be sure it returns to the idle position
whenever you release the accelerator pedal'
LOCKNUT
lnstallation
Dl6Y5, Dr6Y8, D16Y, €ngine:
1. Open the throttle valve fully, then install the throttle
cable in the throttle linkage, and install the cable
housing in the cable bracket.
D16Y5, D16Y8 engins:
LOCKNUT
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.
Hold the cable sheath. removing all slack from the
caDle (cont'dl
11-245