Mercury MerCruiser MCM 454 Mag MPI Service Manual page 584

SERVICE MANUAL NUMBER 23
Rough, Unstable, or Incorrect Idle, Stalling Symptom (Continued)
Index
90-861326--1 MARCH 1999
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1. Check for fuel in pressure regulator
vacuum hose.
2. If fuel is present, replace the fuel
pressure regulator assembly.
Refer to Fuel Metering System in
11
"Description and System Operation"
section.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check for intermittent opens or short
to grounds in the ECT sensor, MAP
sensor and TP sensor circuits. Also
check or throttle linkage sticking,
binding or worn.
12
2. An intermittent failure may not store
a DTC.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check ECM grounds for being
clean, tight and in their proper loca-
tions.
2. Also check that battery cables and
13
ground straps are clean nd secure.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check fuel delivery system items
that can cause the engine to run rich.
14
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check fuel delivery system items
that can cause the engine to run
lean.
15
2. If a problem is found, repair as nec-
essary.
Was a problem found?
1. Check or proper alternator voltage
output.
2. The voltage should be between spe-
16 cified values.
3. If a problem is found, repair as nec-
essary.
Was a problem found?
FUEL INJECTION SYSTEM TROUBLESHOOTING
Go to OBD
11-16
System
Volts
Check
Go to OBD
System
-
Check
Go to OBD
System
-
Check
Go to OBD
System
-
Check
Go to OBD
System
-
Check
Go to OBD
11-16
System
Volts
Check
Go to Step 12
Go to Step 13
Go to Step 14
Go to Step 15
Go to Step 16
Go to Step 17
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