TROUBLE DIAGNOSES — Diagnostic Table (Cont'd) — Symptom 2: Impossible to start — partial combustion
EF & EC-40flowchartDiagnostic Table (Cont'd)
SYMPTOM & CONDITION 2 — Impossible to start — partial combustion
Possible Causes vs. Check Step Matrix
SPECIFICATIONS
POSSIBLE CAUSESMixture ratio
1O
2O
3O
4
5
SPECIFICATIONS
POSSIBLE CAUSESFuel pressure (too low)
1
2
3
4O
5
SPECIFICATIONS
POSSIBLE CAUSESIgnition timing
1
2
3
4
5O
FUEL SYSTEM
POSSIBLE CAUSESFuel pump
1O
2
3
4
5
FUEL SYSTEM
POSSIBLE CAUSESFuel pump relay (open circuited)
1O
2
3
4
5
FUEL SYSTEM
POSSIBLE CAUSESInjectors (clogged)
1
2O
3
4
5
SERVICE PROCEDURE
Diagnostic Service Procedure — Symptom 2: Impossible to start — partial combustion
1
LISTEN — Listen for fuel pump operating sound. (Fuel pump, SEF279G)
N.G.
N.G. — Check fuel pump and/or related circuits. [See page EF & EC-102.]
O.K.
2
LISTEN — Listen for injector operating sound. (Injector, SEF280G)
N.G.
N.G. — Check injector circuit. [See page EF & EC-112.]
O.K.
3
APPLY VACUUM PRESSURE — Remove vacuum hose from pressure regulator, and apply vacuum and/or pressure, and try to start. (SEF291G)
O.K. (try to start)
return to step 3
Improved
4
MEASURE — Fuel pressure gauge — Connect vacuum hose to pressure regulator and measure fuel pressure. (SEF286G) — Check idle mixture ratio. [See page EF & EC-25.]
5
CHECK — Timing light — Check ignition timing. (SEF284G)
N.G. (adjust)
6
N.G. — Adjust ignition timing. [See page EF & EC-22.]
See also
EF & EC-102Diagnostic Procedure 10 — FUEL PUMP (Not self-diagnostic item)EF & EC-112TROUBLE DIAGNOSES — Diagnostic Procedure 15 — INJECTOR (Not self-diagnostic item)EF & EC-22Direct Ignition System (Cont'd) — Checking Ignition Timing and Idle SpeedEF & EC-25IDLE SPEED/IGNITION TIMING/IDLE MIXTURE RATIO INSPECTION