Page 262 of 1413
PGM-FI System
11-72
While measuring voltage betweenDlO 1+) terminal and 426 l-)terminal, turn the headlighr switchto the second position (a) {low).
Does the voltage drop whenthe headlights are turned on?
Subrtitute . known-good ECMand rochock. lt 3ymptom/indic€-tion goos away, ioplaco th6 origi-nal ECM.
Electrical Load Detector (ELD) (cont'd)
425 t-t D10 l+), Doos Volrago Orop? ----------------J
Page 275 of 1413

ldle Control System
Alternator (ALTI FR Signal
This signals the ECM when the Alternator (ALT) as charging.
D9 l+)
Inspection ot ALT FR Sign.l.
Connect the tost harness betweenthe ECM and connectors. Discon-nect "D" connector from themain wire harnoss only, not theECM lsee page 11-37).
Turn the ignition switch ON.
Measure voltage between D9 (+ )terminal and A26 {-}terminal.
Sub{inno s known-good ECMand redrack. It pro.ctibod volt gola now availablg, ropllco tha orlg-inal ECM.
ls there approx. 5 V?
Turn the ignition switch OFF.
Reconnect "D" connector to themain wire harness,
Start tho engino. Hold the engine
!L3,099 rpm with no load (A/T in
LN] or El position, M/T in neutral)until the radiator tan comes on,rhen let it idle.
Measuro voltage between Dg (fl
terminal and 426 (- I terminal.
Does the voltage decreasewhen headlights and .eardelogger are turned on?Turn ths ignition switch OFF.
ALT FR rignal is OK.
o oo oo o ooooo
ooooooooooo
Voh.go?
ooooooooooo
ooooooooooo
1 1-86
(To page 1 1-87)
=-
Page 279 of 1413
ldle ControlSystem
Brake SwitchSignal
This signals the ECM when the brake pedal is depressed.
11-90
Inlp.ction ot Brd(. Switcfi Siignal.
Are the brake lights on withoutdepressinO the brake pedal?ltuoacl ths braka .wilch {!.a !ac-don 191,
Inspect STOP, HORN (20 Allusein the undeFhood fuse/relav box.Oo the brake lights come on?
R.pl!c. STO P,HOR {2O A) tu...R.pdr dbrt In WtlT/GBI wlrr batu..nb?!ka .wltch a.rdsToP, HOR[{ (20 A}lura.
ls the luse OK.?
- Ropalr opon In WHT/GRN wirobatwoan b'lka lwltch andSTOP, HORTI {20 Al lu!o.- InlDect tho braka awitch la6a.6cdon 19).
Connect tho t€st harness to themain wire hamess only, not to theECM {see page 11-37).
(To page 'l1-91)
Page 284 of 1413

- ldle Speed Setting
Inspoction/Adiustment
NOTE:
a When the idle speed set, check the following items:
- The MIL has not been reported on.- lgnition timing- Spark plugs- Air cleaner- PCV svstem
a (Canada) Pullthe parking brake lever up. Stan the en-
gine, then check that the headlights are off.
1 Start the engine. Hold the engine at 3,000 rpm with
no load (A/T in S or @ position, M/T in neutral)
until the radiator tan comes on, then let it idle.
2. Connect a tachometer.
3. Disconnect the 2P connectot trom the ldle Air Con-
trol {lAC) valve.
Start the engine with the sccelerator pedal slightly
depressed. Stabilize the rpm at 1 ,OOO, then slowly
release the pedal until the engine idles.
Check idling in no-load conditions: headlights, blower
fan, rear defogger, radiator fan, and ai. conditioner
are not operatrng.
ldl€ spood should bo;
81881 ongino:
MlT48O ! 50 rym
An48O I 50 rpm
lin@or@oosition)
818C7 engine:48O ! 50 rym
Adjust the idle speed, if necessary, by turnmg the
idle adiusting screw.
NOTE: After adiust the idle speed in this step, check
the ignition timing (see section 231.
lf it is out ot spec. go back to step 4.
4.
e
Turn the ignition switch OFF.
Reconnect the 2P connector on the IAC valve, then
remove the BACK UP (7.5 A) fuse in the under-hood
tuse/relav box for 1O seconds to reset the ECM.
Restart 8nd idle the engine with no-load conditions
for one minute, then check the idle speed.
NOTE: (Canada) Pull the parking brake lever up.
Start the engine, then check that the headlights ate
off.
ldlo speed should be;
81881 ongino:
MTf75O ! 50 rpm
AIT75O t 50 rpm
(in[]or@positionl
818C1 engine: 750 1 50 rpm
(cont'd)
11-95
Page 285 of 1413
ldle Control System
ldle Speed Setting (cont'd)
10.
9. ldle the engine for one minute with headlights {Low}
ON and check the idle sDeed.
ldla sp6od should bo;
81881 engine:
M/T750 i 50 rpm
An75O t 50 rpm
{in $ or p] positionl
818C1 engine: 75O 1 50 rpm
Turn the headlights off.
ldle the engine for one minute with heater tan switch
at Hl and air conditioner on, then check the idle
speeo.
ldls spood should bo;
81881 ongino:
M/T82O 1 50 rpm
AN840 1 50 rpm(in [N] or lll position)
818C1 engino: 85O t 50 nm
NOTE: lf the idle speed is not within specitication,
see System Troubleshooting Guide on page 1 1-78.
11-96
Page 309 of 1413

lntake Air System
Throttle Body
Description
The throttle body is ot the single-barrel side-draft 1ype.
The lower portion of the throttle valve is heated by en-gine coolant from the cylinder head. The idle adjusting
screw which increases/dec.eases bvDass air and the
Evaporative Emission (EVAP) Control Canister port are
located on the top of the throttle body.
IOLE AOJUSTING
THROTTLESTOP SCREW(Non-adiustsb16l
11-120
Insoection
CAUTION: Do not adiust the thlottle stop screw. lt ispreset at the lactory.
1. Start the engine. Hold the engine at 3,OOO rpm with
no load (A/T in S or E position, M/T in neutral) until
the radiator fan comes on, then let it idle.
2. Disconnect the vacuum hose (to the EVAP control
canister) from the top of the throttle body; connect
a vacuum, gauge to the throttle body.
VACUUM PUMPGAUGEA973X-O41-XXXXX
5.
3. Allow the engine to idle and check that the gauge
indicates no vacuum.
a li there is vacuum, check the throttle cable (see
page 1 1-'l 18, 119).
Check that vacuum is indicated on the gauge when
the throttle is opened slightly from idle.
a lf the gauge indicates no vacuum, check the throt-
tle body port. lf the throttle body port is clogged.
clean it with carburetor cleaner.
Stop the engine and check that the throttle cable
operates smoothly without binding or sticking.
a lf there are any abnormalities in the above steps,
check for:
- Excessive wear or Dlav in the throttle valve shaft.
Sticky or binding throttle lever at full close po-
srtron.
Clearance between throttle stop screw and throt-
tle lever at tull close Dosition.
Page 319 of 1413

Emission Control System
SystemDescription
The emission control system includes a Three Way Cata-
lytic Convener (TWC), Positive Crankcase Ventilation(PCV) system and Evaporstive Emission {EVAP) Contfol
syst€m. The emission control system is designed to meet
federsl and stats emission standards.
Tailpipe Emission
Inspection
f!fifil oo nor amoro ou]rng rnr! Foacqurr. ^!op
any open flame away from yout wotk atca.
Start the engine. Hold the engine at 3,OOO rpm with
no load (A/T in @ or@ position, M/T in neutral) until
the radiator fan comes on, then let it idle,
Connect a tachometer.
Check and adiust the idle speed, if necessary (sss
page 1 1-95).
Warm up and calibrate the CO meter according to
the meter manutacturer's inst.uctions.
Check idle CO with the headlights, hester blower,
rear window defogger, cooling fan, and air condition-
er otf.
NOTE: (Canada) Pull the parking br8ke lever up.
Stan the engine, then check that the headlights are
off.
CO meter should indicate 0.1 maximum.
11-130
Page 323 of 1413
Emission Control System
Positive Crankcase Ventilation (PCVI System
Description
The Positive Crankcase Ventilation (PCV) system is
designed to prevent blow-by gas {rom escaping to the
atmosphsre. The PCV valve contains a spring-loadsd
plunger. When the Bngine starts, the plunger in the PCV
valve is lifted in proportion to intake manifold vacuum
and the blow-by gas is drawn directly into th€ intak€
manifold.
FCV VALVE
.F: ILOW-BY VAFORer FRESH AIR
11-134
Insp€cdon
1. Check th€ PCV hos6s and connections tor lsaks and
clogging.
At idle, mak6 sur€ th6fe is a clicking sound from th6
PCV valve when the hose between rcV valve and
intake manifold in lightly pinched with your fingors
or oli€rs.
a lf thera is no clicking sound, ch6ck the PCV valve
grommet for cracks or damage. ll the grommet
is OK, reolace the PCV valve and recheck.
2.
SREATHER
Gontly pinch hero.