Toyota 4A-FE Repair Manual page 93

Fl-22 EFI SYSTEM - Troubleshooting
i
OK CONTINUED FROM PAGE Fl-21
CHECK COLD START INJECTOR 1. Cold start injector
{See page Fl-105) BAD 2 . Start injector time switch
(See page Fl-13 7)
!
OK
CHECK FUEL PRESSURE
~
-
1. Fuel pump (See page Fl-94)
(See page Fl-97) BAD
2. Fuel filter
3. Fuel pressure regulator
(See page Fl-109)
i
OK
CHECK INJECTORS Injectors - Clogged
-
(See page Fl-111)
BAD
i
OK
CHECK EFI ELECTRONIC CIRCUIT
--
1. Wiring connections
USING VOLT/OHMMETER BAD
2.
Power to ECU
(See page Fl-34)
( 1) Fusible link(s)
(2) Fuse(s)
(3) EFI main relay
3. Air
flow meter (w/ Air flow meter)
4 . Vacuum sensor (w/o Air flow meter)
5. Water temp. sensor
6. Intake air temp . sensor
7. Throttle position sensor
B.
Injection signal circuit
(1) Injector wiring
(2) Fuel cut RPM (See page Fl-153)
(3) ECU
9. Oxygen sensor (w/ TWC)
~
OK
(w/o
TWC)
- -
I
Variable resistor
I
CHECK VARIABLE RESISTOR BAD
(See page Fl-142)
SYMPTOM - MUFFLER EXPLOSION (AFTER FIRE)-Rich Fuel Mixture-Misfire
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
(See page Fl-25)
!
Normal
CHECK IGNITION TIMING
1. Connect terminals TE 1 and E1 of the
check connector
2. Check ignition timing.
Standard:
10° BTDC
@
idle
!
OK
CONTINUED ON PAGE Fl-23
Malfunc
code(
NO
_ _ Diagnostic code(s)
ti on
s)
--
4A-FE (See page Fl-28)
Ignition timing - Adjust
4A-FE (See page EM-20)