Muffler Explosion (After Fire) - Toyota MR2 1988 Repair Manual

Fl-18 EFI SYSTEM - Troubleshooting
SYMPTOM- MUFFLER EXPLOSION (AFTER FIRE)
-Rich Fuel Mixture-Misfire
CHECK DIAGNOSIS SYSTEM Malfunction Diagnosis code(s) (See pages Fl-24 to 27)
Check for output of diagnosis code.
code
(See page Fl-21)
~
Normal code
CHECK IGNITION TIMING
NO
Ignition timing - Adjust
1. Short terminals T and E, of the
(See page IG-11)
check connector.
2. Check ignition timing.
STD: 1 0° BTDC
@
Idling
(w/short-circuited T- E,)
l
OK
CHECK IDLE SPEED
NO
Idle speed Adjust (4A-GE)
STD: 800 rpm ISC system (4A-GZE)
l
OK
CHECK COLD START INJECTOR
BAD
1. Cold start injector
(See page Fl-115)
2. Start injector time switch
(See page Fl-11 5)
!
OK
CHECK FUEL PRESSURE
BAD
Fuel pressure regulator
(See page Fl-65 or 68)
!
OK
CHECK INJECTORS (See page Fl-80)
BAD
Injectors - Leakage
l
OK
CHECK SPARK PLUGS
NO
1. Spark plug
Plug gap: 1.1 mm (0.043 in.)
2. Compression pressure
-Note-
Limit (at 250 rpm):
Check compression pressure and valve
4A-GE
10.0 kg/cm2
clearance if necessary. ( 142 psi, 981 kpa)
(See page EM- 14)
4A-GZE
8.5 kg/cm 2
(120 psi, 834 kpa)
3. Valve clearance (cold)
STD: IN 0.15- 0.25 mm
(0.006 - 0.010 in.)
EX 0.20 - 0.30 mm
(0.008 - 0.012 in.)
!
OK
CHECK EFI ELECTRONIC CIRCUIT
BAD
1 . Throttle position sensor
USING VOLT/OHMMETER 2. Injection signal
(See page Fl-33 or 48)
(1) Injector wiring
(2) Fuel cut RPM (See page Fl-128)
(3) Computer (ECU)
(4) Resistor (4A-GZE)
3. Oxygen sensor