Page 1029 of 2389

1. ISC system
(1) Wiring connection(s)
(2) ISC valve (Seepage FI±116 or 118)
(3) ECU (test by substitution)
2. (3S±FE)
Idle speed ± Adjust (See page EM±19)
CHECK IGNITION TIMING
1. Connect terminals TE1 and E1 of the check connector.
2. Check ignition timing.
Standard: 10° BTDC @ idle CHECK WIRING CONNECTORS AND
RELAYS
Check for a signal change when the connector or relay is
slightly tapped or wiggled.
1. Oil filler cap
2. Oil dipstick
3. Hose connections
4. PCV hoses
5. EGR system ± EGR valve stays open1. Connector(s)
2. ER main relay (See page FI±121)
3. Circuit opening relay (See page FI±123) CHECK DIAGNOSIS SYSTEM
Check for output of diagnosis code.
(See page FI±22)
CHECK DIAGNOSIS SYSTEM
Check for output of diagnosis code.
(See page FI±22)
SYMPTOM ± ENGINE SOMETIMES STALLS
SYMPTOM ± ROUGH IDLING AND/OR MISSING
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE
Ignition timing Adjust
(See page IG±17 or 21) CHECK AIR FLOW METER
(See page FI±104)
CHECK IDLE SPEED
Standard: 700 + 50 rpmDiagnostic code(s) (See page FI±25 or 27)
Diagnostic code(s) (See page FI±25 or 27)
OK CONTINUED 4N PAGE FI±16
Element ± Clean or replace
CHECK AIR FILTER
Malfunction
code(s)
Malfunction
code(s)
Air flow meter
Normal code
Normal code
BAD
BADBAD
BAD BAD
± EFI SYSTEMTroubleshootingFI±15
Page 1058 of 2389
Check that there is voltage between ECU terminal +B or +B1 and
body ground. (IG SW ON) No voltage between ECU terminals +B or +B1 and El.
(IG SW ON)
Check wiring between ECU terminal E1 and body
ground.
Check wiring between ER main
relay and battery.Check fuse, fusible link and
ignition switch.
Check ER main relay.Try another ECU.
Repair or replace. Repair or replace.
Repair or replace.
Ignition SW ON
STD voltageTerminals
Condition
Replace.
Trouble
BAD BADBAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±34
Page 1067 of 2389
Check that there is voltage at STA (50) terminal of starter.
(IG SW START) STD voltage: 6 ± 14 v Check fusible link, battery, wiring, ignition
switch clutch start switch, starter relay and
neutral start switch..Check wiring between ECU terminal E1 and body
ground. No voltage between ECU terminals STA and E1.
OG SW START)
Check wiring between ignition switch
terminal ST1 and starter terminal STA (50).Check wiring between ECU terminal STA
and ignition switch terminal ST1.
Check starter
operation.
Repair or replace.
Repair or replace.Repair or replace.
Try another ECU.STD voltage
Check starter.
No voltage
Cranking
Terminals ConditionTrouble
BAD
BADBAD BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±43
Page 1077 of 2389
Check that there is voltage between ECU terminal M±REL and body
ground. (IG SW ON)Check that there is voltage between ECU terminal IG SW and body
ground. (IG SW ON).
There is no voltage between ECU terminals M±REL and El.
(IG SW ON)There is no voltage between ECU terminals IG SW and El.
(IG SW ON)
Check wiring between ECU terminal E 1 and body
ground.Check wiring between ECU terminal E t and body ground.
Check EFI main relay and wiring
harness. (See page F!±121 )Check fuse, fusible link and
ignition switch.
Repair or replace.Repair or replace. Repair or replace.
Try another ECU.
Try another ECU.
Try another ECU.
wM±REL ± E1 wIG SW ± E1
Replace. BADBAD
BAD
BAD
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±53
Page 1078 of 2389
Check that there is voltage between ECU terminal +B (+B1)
and body ground. (IG SW ON) There is no voltage between ECU terminals +B (+B1) and
E1. (IG SW ON)
Check wiring between ECU terminal E1 and body
ground. .
Check fuse, fusible link and wiring
harness.
Refer to M±REL ± E1 trouble
section.Check EFI main relay.
(See page FI±121 )
w+B(+B1)±E1
Repair or replace. Try another ECU.Repair or replace.
Replace.BAD
BAD
BAD
± EFI SYSTEMTroubleshooting with Volt ohmmeterFI±54
Page 1087 of 2389
Check that there is voltage between ECU terminal +B (+Bl)
and body ground. (IG SW ON) There is no voltage between ECU terminals ISC 1 ± ISC4
and E1 . (IG SW ON)
Check wiring between ECU terminal E1 and body ground.
Check wiring between ECU and EFI main
relay. Check ISC valve.
(See page FI±118)Refer to No. 1.
(See page FI±52)
Try another ECU. ..Replace ISC
valve.
Repair or replace.Repair or replace.STD voltage
No voltage
IG SW ON
Terminals ConditionTrouble
BADBAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±63
Page 1136 of 2389
INSPECTION OF EFI MAIN RELAY
1. INSPECT RELAY CONTINUITY
(a) Using an ohmmeter, check that there is continuity between
terminals 1 and 3.
(b) Check that there is no continuity between terminals 2
and 4.
If continuity is not as specified, replace the relay.
2. INSPECT RELAY OPERATION
(a) Apply battery voltage across terminals 1 and 3.
(b) Using an ohmmeter, check that there is continuity between
terminals 2 and 4.
If operation is not as specified, replace the relay.
± EFI SYSTEMElectronic Control System (EFI Main RelayFI±122
Page 1137 of 2389
INSPECTION OF CIRCUIT OPENING
RELAY
1. INSPECT RELAY CONTINUITY
(a) Using an ohmmeter, check that there is continuity
between terminals STA and E1.
(b) Check that there is continuity between terminals B
and FC.
(c) Check that there is no continuity between terminals B
and FP.
If continuity is not as specified, replace the relay.
2. INSPECT RELAY OPERATION
(a) Apply battery voltage across terminals STA and E1.
(b) Using an ohmmeter, check that there is continuity between
terminals B and FP.
(c) Apply battery voltage across terminals B and FC.
(d) Check that there is continuity between terminals B
and FP.
If operation is not as specified, replace the relay.
Circuit Opening Relay
± EFI SYSTEMElectronic Control System (Circuit Opening Relay)FI±123