Removal
Engine removal is not required for this procedure
!!!s@ Make sure iacks and salety stands are
f ta"eata"ea propetty and hoist brackets are attached to the
correct positions on the engine.
CAUTION:
. Use tender covels to avoid damaging painted sul-
faces.
o To avoid damage, unplug the wiling connectors
carefully while holding the connector portion to
avoid damage.
. To avoid damaging the cylinder head, wait until the
engine coolant temperature drops below 100"F
{38"C} before loossning the tetaining bolts.
NOTE:
o Mark all wiring and hoses to avoid misconnectlon
Also, be sure that they do not contact other wiring or
hoses, or interfere with other parts.
. Inspect the timing belt before removing the cylinder
h ead.
. Turnthe crankshaft pu lley so that the No. lpistonisat
top dead center (see Page 6-21)
'1. Disconnect the negative terminal from the battery'
Drain the engine coolant (see page'10-7).
a Remove the radiator cap to speed draining.
Remove the intake air duct and air cleaner housing
(see page 5 3).
Remove the mounting bolt and lock bolt. then
remove the power steering (P/S) pump belt and
pump (see page 5'5).
Loosen the idler pulley center nut and adjusting
bolt' then remove the air conditioning (A'lc) com-
pressor belt (see Page 5-6).
Loosen the mounting nut and lock bolt. then
remove the alternator belt (see page 6-19).
Remove the P/S pump bracket (see page 5-12).
3.
4.
2.
6.
1.
8. Remove the throttle cable by loosening the locknut,
then slip the cable end out of the throttle linkage
NOTE:
. Take care not to bend the cable when removing it
Always replace any kinked cable with a new one
. Adjust the throttle cable when installing (see sec-
tion 1 1).
D16Y7 engine:
Dl6Y5, Dl6Y8 engines:
THFOTTLECABLE
(cont'd)
6-27
LOCKNUT
CABLE
13. Remove the upper radiator hose' heater hose and
water bYPass hose
WATEREYPASSHOSEUPPERRADIATORHOSE
14.
HEATERHOSE
Remove the engine wire harness connectors and
wire harness clamps from the cylinder head and the
intake manifold.
o Four fuel injector connectors
. Engine coolant temperature (ECT) sensor con-
nector
a
a
a
ECT switch connector
ECT gauge sending unit connector
Throttle position sensor connector
Manitold absolute pressure (MAP) sensor con-
nector
Primary heated oxygen sensor (primary HO2S)
connector
Secondary heated oxygen sensor (secondary
HO2S) connector (D16Y7 engine)
Exhaust gas recirculation (EGR) valve lift sensor
connector (D16Y5 engine)
. VTEC solenoid valve connector (Dl6Y5, D16Y8
engrnes)
. VTEC pressure switch connector (D16Y5. D16Y8
engrnes,
. ldle air control (lAC) valve connector
15.Remove the spark plug caps and distributor from
the cylinder head.
Remove the uPPer bracket.
NOTE:
. Use a jack to support the engine before the
upper bracket is removed.
. Make sure to place a cushion between the oil
pan and the jack.
12 x 1.25 mm
74 N.m {7.5 kgf m.
sil lbl.ftl
UPPERBRACKET
'17. Remove the cylinder head cover'
CYLINDERHEAD COVER
(cont'd)
6-29
Removal
Engine removal is not required for this procedure.
!@@ Make sure jacks and safety stands are placed
properly and hoist brackels are attached to correst posi-
tion on the engine,
CAUTION:
o Use fender covers to avoid damaging painted sur-
faces.
To avoid damage, unplug the wiling connectors
carelully while holding the connector portion.
To avoid damaging the cylinder head, wait until the
engine coolant temperature drops below 100"F {38'Cl
before loosening the retaining bolt.
NOTE:
. Unspecified items are common.
. Mark all wiring and hoses to avoid misconnection.
AIso, be sure that they do not contact other wiring or
hoses or interfere with other parts.
o Inspect the timing belt before removing the cylinder
n eao.
. Turn the crankshaft pulley so that the No. 1 piston is
at top dead center (see page 6-64).
1. Disconnect the negative terminal from the battery.
Drain the engine coolant {see page 10-7).
. Remove the radiator cap to speed draining.
Remove the strut brace (see page 5-2).
Remove the intake air duct and air cleaner housing
(see page 5-3).
Remove the adjusting bolt and mounting bolt, then
remove the power steering (P/S) pump belt and pump
(see page 5 5).
2.
3.
4.
\
ADJUSTING
6. Loosen the idler pulley bracket bolt and adjusting
bolt, then remove the air conditioning (A/C) com-
pressor belt.
IDLER PULLEY BRACKETBOLT10 x 1.25 mm44 N.m {4.5 kg,l.m, 33 lbt.ft}
7. Loosen the mounting nut and lock bolt, then remove
the alternator belt.
LOCK BOLT8 x 1.25 mm24 N.m {2.4 kgf.m,17 tbtftl
ALTERNATORBELT10 x 1.25 mm,l,l N.m {4.5 kgf.m,33 tbf.ft,
(cont'd)
6-67
WATER BYPASS
HOSE
14. Remove the upper radiator hose, heater hose and
water bvpass hose.
HEATER
Remove the engine wire harness connectors and wlre
harness clamps from the cylinder head and the intake
manifold.
Four fuel injector connector
Engine coolant temperature (ECT) sensor connec-
tor
ECT gauge sending unit connector
ECT switch connector
ldle air control (lAC) valve connector
Manifold absolute pressure (MAP) sensor connec-
tor
Throttle position sensor connector
Primary Heated oxygen sensor (Primary HO2S)
connecror
VTEC solenoid valve connector
15.
a
a
a
a
a
\
16.
17.
Remove the spark plug caps and distributor form
the cylinder head.
Remove the upper bracket.
NOTE:
. Use a jack to support the engine before removing
the upp€r bracket is removed.
. Place a cushion between the oil panandthejack.
12 x 1.25 fin74 N.m 17.5 kgtm,
UPPER BRACKET
18. Remove the cylinder head cover.
{cont'd)
6-69
Dl6Y5 engine ('96 - 97 modelsl:
o
,6i
@
o@€)@o
@(il(i'
PRIMARY HEATED OXYGEN SENSOR {PRIMARY HO2S,
SENSOR 1'SECONDARY HEATED OXYGEN SENSOR (SECONDARY
HO2S. SENSOR 2l
MANIFOLD ABSOLUTE PRESSURE {MAP) SENSOR
ENGINE COOLANT TEMPERATURE (ECTI SENSOR
INTAKE AIR TEMPERATURE IIAT) SENSOR
KNOCK SENSOR (KS)
CRANKSHAFT SPEED FLUCTUATTON (CKF} SENSOR
IOLE AIR CONTROL (IAC} VALVE
THROTTLE BODY (TBI
FUEL INJECTORFUEL PULSATION DAMPER
FUEL FILTERFUEL PRESSURE REGULATORFUEL PUMP IFPIFUEL TANK
:li Vacuum hose No*: CVT only
FUEL TANK EVAPORATIVE EMISSTON {EVAP) VALVE
AIR CLEANERRESONATORPOSITIVE CRANKCASE VENTIL/ATION IPCVI VALVE
EXHAUST GAS RECIRCULATION IEGR) CONTROL
SOLENOID VALVEEXHAUST GAS RECIRCULATION (EGRI VALVE
EXHAUST GAS RECTRCULATION IEGRI VALVE LIFT
SENSOREVAPORATIVE EMISSION IEVAPI PURGE CONTROL
SOLENOID VALVEEVAPORATIVE EMISSION {EVAP} CONTROL CANISTER
EVAPORATIVE EMISSION {EVAP} TWO WAY VALVE
THREE WAY CATALYTIC CONVERTER (TWCI
{Do(D
@@
@@
@
@@@
(cont'd)
1 1-19
!'a
System Description
Vacuum Connections (cont'd)
D16Y5 engine ('98 modet):
-: Vacuum hose No,*: CW only
(9 POSITIVE CRANKCASE VENTILATION {PCV} VALVE?!J EXHAUST GAS BECIRCULATION (EGR}CONTROLSOLENOIO VALVE'1 ExHAUST GAs RECIRCULATIoN IEGRI VALVE22 EXHAUST GAS RECIRCULATION {EGR} VALVE LIFISENSOR€J EvApoRATtvE EMtsstoN {EvAp} puRGE coNTRoLSOLENOID VALVEq4 PURGE JOINT@ EVAPoRATIVE EMIssIoN {EVAP) coNTRoL CANISTER@ EVAPORATIVE EMISSION IEVAP} BYPASS SOLENOIDVALVE?? EVAPORATIVE EMISSION {EVAP) THREE WAY VALVEITII EVAPORATIVE EMISSION IEVAP} CONTROL CANISTERVENT SHUT VALVEO FUEL TANK PRESSURE sENsoRQlI EVAPORATIVE EMISSION {EVAP}TWO WAY VALVE8' THREE WAY CATALYTIC CONVERTER {TWCI
il) PRIMAFY HEATED OXYGEN SENSOR IPRIMARY HO2S.SENSOR 1)O SECoNDARY HEATEo oxYGEN sENsoR {sEcoNDARYHO2S. SENSOB 2)iq] MANIFOLD ABSOLUTE PRESSURE (MAPI SENSORO ENGINE COOLANT TEMPERATURE IECT) SENSOR5 INTAKE AIR TEMPERATURE {IATI SENSOR! KNOCK SENSOR tKSlO CRANKSHAFT SPEED FLUCTUATIoN {cKF) sENsoFO IDLE AIR coNTRoL {IAc) vALvE99 THROTTLE BODY ITBI@ FUEL INJECToRO FUEL PULSATION DAMPER@ FUEL F -TER@ FUEL PRESSURE REGULAToR[4 FUEL PUMP IFPI(9 FUEL TANK(D FUEL TANK EVAPoRATIVE EMIssIoN IEVAPI VALVEO' AIR CLEANER(D RESoNAToR
11-20
Troubleshooting
Troubleshooting Procedures (cont,dl
ECM/PCM Data
By connecting the OBD ll scan tool or the Honda pGM Tester to the l6p data link connector (DLC), various data can beretrieved from the EcM/PcM. The items Iisted in the table below conform to the sAE recommended practice.The Honda PGM Tester also reads data beyond that recommended bv SAE.understanding this data wil help to find the causes of intermittent fairures or engine probrems,
NOTE:
' The "operating values" given below are approximate values and may be different depending on the environment andthe individual vehicle.. Unless noted otherwise, "at idle speed,, means idling with the engine completely warmed up, Ay'T in position @ or E],M/T in neutral, and the Ay'C and all accessories turned off.
(
DataDescriptionOperating ValueFreeze Data
Diagnostic
Trouble Code(DTC)
lf the ECM /PCM detects a problem, it will store it as acode consisting of one letter and four numbers.Depending on the problem, an SAE-defined code (poxxx)or a Honda-defined code (Plxxx) will be outDut to therester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECM/PCM computes engine speed from the signalssent from the Crankshaft Position sensor.This data is used for determining the time and amount offuel injection,
Nearly the same as
tachometer indication.YES
Vehicle SpeedThe ECM/PCM converts pulse signals from the VehicleSpeed Sensor (VSS) into speed data.Nearly the same as
speedometer indicationYES
Manifold
Absolute
Pressure {MAP)
The absolute pressure caused in the intake manifold bvengine load and speed.With engine stopped:
Nearly the same as atmo-
spheflc pressure
At idle speed:
24 - 31 kPa (180 - 280
mmHg, 7.1 - 11.0 inHg)
YES
Engine Coolant
Temperature
(ECT)
The ECT sensor converts coolant temperature into volt_age and signals the ECM/PCM. The sensor is a thermistorwhose internal resistance changes with coolant temDera_ture. The ECM/PCM uses the voltage signals from theECT sensor to determine the amount of iniected fuel.
With cold engine:
Same as ambient temper,
ature and IAT
With engine warmed up:
176 - 194.F (80 - 90.C)
YES
Heated Oxygen
Sensor {HO2S)(Primary,
Sensor 1)(Secondary
Sensor 2)
The Heated Oxygen Sensor detects the oxygen contentin the exhaust gas and sends voltage signals to theECI\4/PCM. Based on these signats, the ECM/pCM con_trols the airlfuel ratio. When the oxygen content is high(that is, when the ratio is leaner than the stoichiometricratio), the voltage signal is lower.When the oxygen content is low (that is, when the ratiois richer than the stoichiometric ratio), the voltage signalis higher.
0.0 - 1.25 V
At idle speed:
about 0.1 - 0.9 V
NO(Sensor 1)
1 1-86
ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)