Download FUEL SYSTEMS

Engine Cranks but Will Not Run (Continued)
Chart A-3 (3 of 4)
INJ/ECM
FUSE 10A
INJECTORS
IGNITION CONTROL
DIST. REFERENCE “HIGH”
BYPASS
DIST. REFERENCE “LOW”
B
A
INJECTORS
A
B
THROTTLE BODY
MULTI-PORT
TEST DESCRIPTION:
To test for this condition:
Number(s) below refer to circled number(s) on the
diagnostic chart.
•
Disconnect all injectors.
•
Ignition ON.
1. Check for 12 volt supply to injectors. Due to the
injectors wired in parallel, there should be a light
ON on both terminals.
•
Probe CKT 467 and CKT 468 on the ECM
side of injector harness with a test light connected to ground. (Test one injector harness
on each side of engine.) There should be no
light. If light is ON, repair short to voltage.
•
If OK, check the resistance of the injectors.
Should be 12 ohms + 4.
•
Check injector harness connector. Be sure
terminals are not backed out of connector
and contacting each other.
•
If all OK, replace ECM.
2. Check continuity of CKT 467 and CKT 468.
3. All checks made to this point would indicate that
the ECM is at fault. However, there is a possibility
of CKT 467 or CKT 468 being shorted to a voltage
source either in the engine harness or in the injector harness.
Index
5C-58 - ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY)
90-823224--2 796