10-8 SERVICING INFORMATION Complaint Symptom and possible causes Remedy Engine idles poorly. 1. Valve clearance out of adjustment Adjust. 2. Poor seating of valves Replace or repair. 3. Defective valve guides Replace. 4. Worn down camshafts Replace. 5. Too wide spark plug gaps Adjust or replace. 6. Defective ignition coil/plug caps Replace. 7. Defective CKP sensor Replace. 8. Defective ECM Replace. 9. Defective TP sensor Replace. 10. Defective fuel pump Replace. 11. Imbalanced throttle valve Adjust. 12. Damaged or cracked vacuum hose Replace. Engine stalls often. Incorrect fuel/air mixture 1. Defective IAP sensor or circuit Repair or replace. 2. Clogged fuel filter Clean or replace. 3. Defective fuel pump Replace. 4. Defective fuel pressure regulator Replace. 5. Defective ECT sensor Replace. 6. Defective thermostat Replace. E 7. Defective IAT sensor Replace. 8. Damaged or cracked vacuum hose LReplace. Fuel injector improperly operatingP 1. Defective fuel injectors Replace. 2. No injection signal from ECM Repair or replace. M Repair or replace. 3. Open or short circuited wiring connection 4. Defective battery or low battery voltage Replace or recharge. A Control circuit or sensor improperly operating S Replace. 1. Defective ECM 2. Defective fuel pressure regulator Replace. 3. Defective TP sensor Replace. 4. Defective IAT sensor Replace. 5. Defective CMP sensor Replace. 6. Defective CKP sensor Replace. 7. Defective ECT sensor Replace. 8. Defective fuel pump relay Replace. Engine internal parts improperly operating 1. Fouled spark plugs Clean. 2. Defective CKP sensor or ECM Replace. 3. Clogged fuel hose Clean. 4. Out of adjustment tappet clearance Adjust.