Toyota 4A-FE Repair Manual page 89

Fl-18 EFI SYSTEM - Troubleshooting
!
OK
CONTINUED FROM PAGE Fl-17
CHECK AUXILIARY AIR VALVE
(See page Fl-1 31)
i
OK
CHECK FUEL PRESSURE
(See page Fl-97)
i
OK
CHECK INJECTORS
(See page Fl- 1 11)
I
i
OK
CHECK EFI ELECTRONIC CIRCUIT
USING VOLT/OHMMETER
(See page Fl-34)
CHECK DIAGNOSTIC SYSTEM
Check for output of diagnostic code.
(See page Fl-25)
~ Normal code
(w/ AIR FLOW METER)
CHECK AIR FLOW METER
(See page Fl-120)
J ,
OK
(w/o AIR FLOW METER)
CHECK VACUUM SENSOR
(See page Fl-140)
~OK
CHECK WIRING CONNECTORS AND
RELAYS
Check that there is a signal change when
the connector or relay is slightly tapped
or wiggled.
1. Auxiliary air valve
BAD 2. Water hose(s)
3 . Air hose(s)
--
1. Fuel pump (See
page
Fl-94)
BAD 2. Fuel filter
3. Fuel pressure regulator
(See page Fl-109)
Injection condition
BAD
- - - - i
1. Wiring connections
BAD 2. Power to ECU
( 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. Injection signal circuit
(1) Injector wiring
(2) ECU
SYMPTOM - ENGINE SOMETIMES STALLS
Diagnostic cord(s)
Malfunction
4A-FE (See page Fl-28)
code(s)
BAD
-1
Air flow meter
BAD
I
Vacuum sensor
-
-
1 . Connectors
BAD 2. EFI main relay (See page Fl-1 34)
3. Circuit opening relay (See page Fl-135)
I
I