Download FUEL SYSTEMS

Throttle Body Injection Fuel System Diagnosis (Continued)
Chart A-7: (6 of 6)
FROM CHART
A-7 (4 OF 6)
1
2
•
•
•
•
IGNITION “OFF.”
REMOVE FUEL PUMP RELAY.
IGNITION “ON.”
WITH TEST LIGHT CONNECTED TO
GROUND, PROBE FUEL PUMP RELAY
CONNECTOR CAVITY “30” TEST LIGHT
SHOULD BE “ON.” IS IT?
YES
NO
•
•
•
IGNITION “OFF.”
USING FUSED JUMPER, CONNECT
TERMINALS “30” AND “87” OF FUEL
PUMP RELAY CONNECTOR TOGETHER.
IGNITION “ON.”
FUEL PUMP SHOULD RUN. DOES IT?
•
•
CHECK FUEL PUMP RELAY FUSE.
IS IT OK?
YES
REPAIR OPEN CKT
339 OR 902
YES
3
•
•
•
CHECK FOR:
• OPEN WIRE IN CKT 120.
• OPEN PUMP GROUND CKT 150. IF OK,
REPLACE FUEL PUMP.
NO
YES
4
•
•
•
CONNECT TEST LIGHT TO GROUND
AND PROBE CAVITY “85” OF THE FUEL
PUMP RELAY CONNECTOR.
IGNITION “ON.”
TEST LIGHT SHOULD BE “ON” FOR
2 SECONDS AND THEN GO “OFF.”
DOES IT?
REPAIR OPEN
GROUND CKT 450
YES
•
•
•
•
•
REPAIR SHORT TO
GROUND IN CKT 339
AND REPLACE FUSE
NO
IGNITION “OFF.”
DISCONNECT FUSED JUMPER.
CONNECT TEST LIGHT TO BATTERY POSITIVE
B+ AND PROBE CAVITY “86” OF THE
FUEL PUMP RELAY CONNECTOR.
LIGHT SHOULD BE “ON.” IS IT?
•
NO
NO
REPLACE FUEL PUMP RELAY AND RETEST.
IF STILL NO PRESSURE, CHECK THE FOLLOWING:
VAPOR LOCK CONDITION.
RESTRICTED FUEL LINE.
DISCONNECTED HOSES.
PROPER FUEL LEVEL.
IF OK, REPLACE FUEL PUMP.
CHECK FOR OPEN
IN CKT 465. IF OK,
REPLACE ECM.
Index
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ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-71