SERVICE MANUAL NUMBER 23
TROUBLESHOOTING
IMPORTANT INFORMATION
Section 1C - Troubleshooting
1
C
Table of Contents
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . 1C-2
Used Spark Plug Analysis . . . . . . . . . . . . . . 1C-3
Spark Plug Analysis . . . . . . . . . . . . . . . . . . . 1C-4
Normal Condition . . . . . . . . . . . . . . . . . . . 1C-4
Chipped Insulator . . . . . . . . . . . . . . . . . . . 1C-4
Wet Fouling (Oil Deposits) . . . . . . . . . . . 1C-4
Cold Fouling . . . . . . . . . . . . . . . . . . . . . . . 1C-5
Overheating . . . . . . . . . . . . . . . . . . . . . . . 1C-5
High Speed Glazing . . . . . . . . . . . . . . . . . 1C-5
Scavenger Deposits . . . . . . . . . . . . . . . . 1C-6
Pre-Ignition Damage . . . . . . . . . . . . . . . . 1C-6
Reversed Coil Polarity . . . . . . . . . . . . . . . 1C-6
Splashed Deposits . . . . . . . . . . . . . . . . . . 1C-7
Mechanical Damage . . . . . . . . . . . . . . . . 1C-7
Poor Boat Performance and/or Poor
Maneuverability . . . . . . . . . . . . . . . . . . . . . . 1C-8
Improper Full Throttle Engine RPM . . . . . . 1C-9
RPM Too High . . . . . . . . . . . . . . . . . . . . . 1C-9
RPM Too Low . . . . . . . . . . . . . . . . . . . . . . 1C-9
Engine Cranks Over But Will Not Start
Or Starts Hard . . . . . . . . . . . . . . . . . . . . . . 1C-10
Important Information . . . . . . . . . . . . . . 1C-10
Fuel System Rich . . . . . . . . . . . . . . . . . . 1C-10
Fuel System Lean . . . . . . . . . . . . . . . . . 1C-10
Miscellaneous . . . . . . . . . . . . . . . . . . . . . 1C-10
Engine Will Not Crank Over . . . . . . . . . . . . 1C-11
Charging System Inoperative . . . . . . . . . . 1C-11
Noisy Alternator . . . . . . . . . . . . . . . . . . . . . . 1C-12
Instrumentation Malfunction . . . . . . . . . . . 1C-12
Radio Noise . . . . . . . . . . . . . . . . . . . . . . . . . 1C-12
Poor Fuel Economy . . . . . . . . . . . . . . . . . . 1C-13
Engine Runs Poorly at Idle . . . . . . . . . . . . 1C-13
Engine Runs Poorly At High RPM . . . . . . 1C-14
Engine Acceleration Is Poor . . . . . . . . . . . 1C-14
Troubleshooting with Vacuum Gauge . . . 1C-15
Engine Noise . . . . . . . . . . . . . . . . . . . . . . . . 1C-15
Important Information . . . . . . . . . . . . . . 1C-15
Valve Cover Area . . . . . . . . . . . . . . . . . . 1C-16
Cylinder Area . . . . . . . . . . . . . . . . . . . . . 1C-16
Camshaft Area . . . . . . . . . . . . . . . . . . . . 1C-17
Crankshaft Area . . . . . . . . . . . . . . . . . . . 1C-17
Miscellaneous . . . . . . . . . . . . . . . . . . . . . 1C-18
Oil Pressure . . . . . . . . . . . . . . . . . . . . . . . . . 1C-19
Miscellaneous . . . . . . . . . . . . . . . . . . . . . 1C-19
Low Oil Pressure . . . . . . . . . . . . . . . . . . 1C-20
High Oil Pressure . . . . . . . . . . . . . . . . . . 1C-20
Excessive Oil Consumption . . . . . . . . . . . . 1C-21
Water In Engine . . . . . . . . . . . . . . . . . . . . . . 1C-22
Important Information . . . . . . . . . . . . . . 1C-22
Water on Top of Pistons . . . . . . . . . . . . 1C-23
Water in Crankcase Oil . . . . . . . . . . . . . 1C-23
Engine Overheats . . . . . . . . . . . . . . . . . . . . 1C-24
Mechanical . . . . . . . . . . . . . . . . . . . . . . . 1C-24
Engine Overheats . . . . . . . . . . . . . . . . . . . . 1C-25
Cooling System . . . . . . . . . . . . . . . . . . . 1C-25
Insufficient Water Flow from Belt
Driven Seawater Pickup Pump . . . . . 1C-26
Power Steering . . . . . . . . . . . . . . . . . . . . . . 1C-27
Poor, Erratic or No Assist . . . . . . . . . . . 1C-27
Noisy Pump . . . . . . . . . . . . . . . . . . . . . . . 1C-28
Fluid Leaks . . . . . . . . . . . . . . . . . . . . . . . 1C-28
90-861326--1 MARCH 1999
Page 1C-1
| 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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