DETONATION/SPARK KNOCK
Definition: A mild to severe ping, usually worse under acceleration or heavy load. The engine
makes sharp metallic knocks that change with throttle opening.
PRELIMINARY CHECKS
Perform the visual/physical checks as described at the start of “Troubleshooting Charts” section.
CHECK FUEL SYSTEM FOR:
1.
2.
3.
Contaminated fuel.
Poor fuel quality and proper octane rating.
Fuel pressure within specification.
CHECK IGNITION SYSTEM FOR:
1.
2.
Proper ignition timing.
Proper operation of Knock Sensor ( KS) system. Ensure wires are routed AWAY from secondary
or primary ignition wires.
3.
4.
5.
Ignition system ground.
Proper heat range and gapped spark plugs.
Incorrect knock sensor or knock sensor module.
CHECK SENSORS AND CONTROLS FOR:
1.
2.
Engine Coolant temperature (ECT) has shifted value.
Binding or sticking Throttle Position (TP) sensor or salt corrosion. Voltage should increase as
throttle is moved toward Wide Open Throttle (WOT).
Index
90-823224--2 796
ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-123
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
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