SERVICE MANUAL NUMBER 23
GENERAL SYSTEM DIAGNOSTICS
Chart A-3 (2 of 5): Engine Cranks But Will Not Run
DIAGNOSTIC AIDS:
This chart assumes that battery voltage and engine cranking speed are OK, and there is
adequate fuel in the tank.
Water or foreign material in fuel system can cause a no start.
A defective MAP sensor may cause a no start or a start and stall condition. To determine
if the MAP sensor is causing the problem, disconnect the electrical connector. The ECM will
then use a default value for the sensor. If the condition is corrected and the connections are
OK, then replace the sensor.
An intermittent may be caused by a poor connection, rubbed through wire insulation or a
wire broken inside the insulation. Check for the following items:
Poor connection or damaged harness. Inspect the ECM harness and connectors for
improper mating, broken locks, improperly formed or damaged terminals, poor terminal to
wire connection, and damaged harness.
If above are all OK, refer to “Hard Start” in “Troubleshooting” section.
Step
Action
Value(s)
Yes
No
Was the “On-Board Diagnostic”
(OBD) System Check performed?
Go to OBD
System Check
1
–
Go to Step 2
Disconnect Throttle Position (TP)
sensor.
Does The Engine Start?
2
3
–
–
Go to Step 14
Go to Step 3
1.
Key “OFF” for minimum of 10
seconds.
2.
3.
Key “ON.”
Listen for fuel pump to run.
Does Fuel Pump Run For 2
Seconds?
Go to Step 4 Go to Chart A-4
Crank engine for 1 second and
listen for fuel pump to run.
Does Fuel Pump Run?
4
5
–
–
Go to Step 5
Go to Step 9
Check
spark.
for
secondary
ignition
Is Adequate Spark Present At All
Cylinders?
Go to Step 6 Go to Chart A-7
Index
90-861326--1
MARCH 1999
Page 5E-67
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
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