8-4 SERVICING INFORMATION
ENGINE
Complaint Symptom and possible causes Remedy
Engine will not start
or is hard to start.
Compression too low
1. Tappet clearance out of adjustment.
2. Worn valve guides or poor seating of valves.
3. Mistimed valves.
4. Excessively worn piston rings.
5. Worn-down cylinder bores.
6. Starter motor cranks too slowly.
7. Poor seating of spark plugs.
Plugs not sparking
1. Fouled spark plugs.
2. Wet spark plugs.
3. Defective ignition coil or camshaft position sensor.
4. Open or short in high-tension cords.
5. Defective crankshaft position sensor.
6. Defective ECM.
7. Open-circuited wiring connections.
No fuel reaching the intake manifold
1. Clogged fuel filter or fuel hose.
2. Defective fuel pump.
3. Defective fuel pressure regulator.
4. Defective fuel injector.
5. Defective fuel pump relay.
6. Defective ECM.
7. Open-circuited wiring connections.
Incorrect fuel/air mixture
1. Throttle position sensor out of adjustment.
2. Defective fuel pump.
3. Defective fuel pressure regulator.
4. Defective throttle position sensor.
5. Defective crankshaft position sensor.
6. Defective intake air pressure sensor.
7. Defective atmospheric pressure sensor.
8. Defective ECM.
9. Defective engine coolant temp. sensor.
10. Defective intake air temp. sensor.
Adjust.
Repair or replace.
Adjust.
Replace.
Replace.
See electrical section.
Retighten.
Clean.
Clean and dry.
Replace.
Replace.
Replace.
Replace.
Repair or replace.
Clean or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Check and repair.
Adjust.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Engine idles poorly.
1. Tappet clearance out of adjustment.
2. Poor seating of valves.
3. Defective valve guides.
4. Worn down camshaft.
5. Too wide spark plug gaps.
6. Defective ignition coil.
7. Defective crankshaft position sensor.
8. Defective ECM.
9. Defective throttle position sensor.
10. Defective fuel pump.
11. Imbalanced throttle valve.
12. Damaged or cracked vacuum hose.
Adjust.
Replace or repair.
Replace.
Replace.
Adjust or replace.
Replace.
Replace.
Replace.
Replace.
Replace.
Adjust.
Replace.
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