Mercury MerCruiser MCM 454 Mag MPI Service Manual page 583

FUEL INJECTION SYSTEM TROUBLESHOOTING
Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued)
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Index
Page 5D-24
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1. Check integrity of the primary and
secondary wiring.
2. Check routing of the wiring.
3. Check condition of IC module,
pick-up coil, distributor cap, rotor
and spark plug wires.
4. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check ignition coil for cracks or car-
bon tracking.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Remove spark plugs, check for wet
plugs, cracks, wear, improper gap,
burned electrodes or heavy depos-
its.
Refer to Distributor Ignition System.
NOTE: If park plugs are gas or oil fouled,
the cause of the fouling must be deter-
mined before replacing the spark plugs.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
Check the injector connections. If any of
the injectors are connected to an
incorrect cylinder, correct as necessary.
Was a problem found?
1. Disconnect all injector harness con-
nectors and install an injector test
light J 34730-2 between the harness
terminal connector of each injector.
2. Crank engine and note light on each
connector. If test light fails to blink at
any one of the connectors, it is a
faulty injector drive circuit harness,
connector or terminal.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check fuel injectors.
Refer to Injector Balance Test in
"General System Diagnostics" sec-
tion.
2. If a problem is found, repair as nec-
essary.
Was a problem found?
SERVICE MANUAL NUMBER 23
Go to OBD
System
- Go to Step 6
Check
Go to OBD
System
Go to Step 7
-
Check
Go to OBD
System
- Go to Step 8
Check
Go to OBD
System
Go to Step 9
-
Check
Go to OBD
System
- Go to Step 10
Check
Go to OBD
System
- Go to Step 11
Check
90-861326--1 MARCH 1999