Engine Controls - Tests W/o Codes: Other Suzuki X-90 I

DIFFICULT OR NO START (CRANKS OKAY)

1. Check for dirty or clogged fuel filter.
2. Check for lack of fuel in tank.
3. Check fuel pressure and volume.
4. Check for contaminated fuel.
5. Check for vacuum leaks.
6. Check for low compression.
7. Check for blown ignition coil fuse.
8. Check for cracked or burned distributor cap or rotor.
9. Check ignition and valve timing.
10. Check spark plugs.
11. Check for adequate spark with a spark tester.
12. Check EGR system.
13. Check pick-up coil air gap.
14. Check for faulty ignitor.
15. Check for faulty pick-up coil.
16. Check for faulty Engine Coolant Temperature (ECT) sensor.
17. Check for faulty Intake Air Temperature (IAT) sensor.
18. Check for faulty Mass Airflow (MAF) sensor.
19. Check for faulty noise suppressor (if equipped).
20. Check for faulty Fast Idle Air (FIA) valve.
21. Check for faulty Idle Air Control (IAC) valve.
22. Check for faulty ignition coil.
23. Check for faulty throttle opener (if equipped).
24. Check for faulty power unit.
25. Check for faulty Camshaft Position (CMP) or Crankshaft Position (CKP) sensor.
26. Check for malfunctioning PCM.
27. Check for malfunctioning PCV valve.
28. Check for malfunctioning electronic fuel injection system.
29. Check for slipped or broken timing belt.

ENGINE MISFIRES OR HAS LACK OF POWER

1. Check ignition and valve timing.
2. Check spark plugs.
3. Check for high resistance in spark plug wires.
4. Check for adequate spark with a spark tester.
5. Check fuel pressure.
6. Check for worn distributor terminals.
7. Check cooling system.
8. Check for dirty or clogged fuel filter.
9. Check for contaminated fuel.
10. Check for clogged air filter.
11. Check for low compression.
12. Check for vacuum leaks.
13. Check for restricted exhaust system.
14. Check for malfunctioning electronic fuel injection system.
15. Check for malfunctioning EGR valve.
16. Check for dragging brakes.
17. Check for slipping clutch.
18. Check for low automatic transmission fluid level.

ROUGH OR UNSTABLE IDLE

1. Check for play in throttle cable.
2. Check for contaminated fuel.
3. Check fuel pressure.
4. Check EVAP control system.
5. Check for clogged air filter.
6. Check for vacuum leaks.
7. Check cooling system condition.
8. Check compression.
9. Check spark plugs.
10. Check for leaking or loose spark plug wires.
11. Check for adequate spark with a spark tester.
12. Check idle speed.
13. Check for cracked or burned distributor cap.
14. Check for worn distributor terminals.
15. Check ignition and valve timing.
16. Clogged MAP sensor vacuum hose.
17. Check for faulty PCM.
18. Check Power Steering Pressure (PSP) switch circuit.
19. Check for faulty Engine Coolant Temperature (ECT) sensor.
20. Check for faulty Intake Air Temperature (IAT) sensor.
21. Check for faulty A/C vacuum switching valve (if equipped).
22. Check for faulty Idle Air Control (IAC) solenoid valve.
23. Check for faulty throttle opener system (if equipped).
24. Check for malfunctioning EGR valve.
25. Check for malfunctioning PCV valve.
26. Check for malfunctioning electronic fuel injection system.

ENGINE HESITATES

1. Check fuel pressure.
2. Check EVAP control system.
3. Check for clogged fuel filter.
4. Check for contaminated fuel.
5. Check for clogged air filter.
6. Check for restricted exhaust system.
7. Check ignition and valve timing.
8. Check spark plugs.
9. Check for adequate spark with a spark tester.
10. Check for high resistance in spark plug wires.
11. Check cooling system condition.
12. Check for low compression.
13. Check for vacuum leaks.
14. Check Throttle Position (TP) sensor.
15. Check for clogged MAP sensor vacuum hose.
16. Check for faulty PCM.
17. Check for faulty Engine Coolant Temperature (ECT) sensor.
18. Check for malfunctioning electronic fuel injection system.
19. Check for malfunctioning EGR valve.

ENGINE SURGES

1. Check spark plugs.
2. Check for adequate spark with a spark tester.
3. Check for high resistance in spark plug wires.
4. Check fuel pressure.
5. Check EVAP control system.
6. Check for clogged fuel filter.
7. Check for damaged or kinked fuel lines.
8. Check for vacuum leaks.
9. Check for cracked or burned distributor cap or rotor.
10. Check ignition and valve timing.
11. Check for faulty PCM.
12. Check for malfunctioning electronic fuel injection system.
13. Check for malfunctioning EGR valve.

SPARK KNOCK/DETONATION

1. Check cooling system.
2. Check fuel pressure.
3. Check EVAP control system.
4. Check spark plugs.
5. Check for high resistance in spark plug wires.
6. Check for adequate spark with a spark tester.
7. Check ignition and valve timing.
8. Check for clogged fuel filter.
9. Check for vacuum leaks.
10. Check for excessive combustion chamber deposits.
11. Check for faulty Throttle Position (TP) sensor.
12. Check for faulty Engine Coolant Temperature (ECT) sensor.
13. Check for engine overheating.
14. Check for faulty MAP sensor.
15. Check for malfunctioning electronic fuel injection system.
16. Check for malfunctioning EGR valve.

POOR FUEL MILEAGE

1. Check for fuel leaks.
2. Check fuel pressure.
3. Check for clogged air filter.
4. Check compression.
5. Check cooling system condition.
6. Check ignition and valve timing.
7. Check spark plugs.
8. Check for adequate spark with a spark tester.
9. Check for high resistance in spark plug wires.
10. Check for faulty Throttle Position (TP) sensor.
11. Check for faulty Engine Coolant Temperature (ECT) sensor.
12. Check for faulty thermostat.
13. Check for faulty PCM.
14. Check for high idle RPM.
15. Check for malfunctioning electronic fuel injection system.
16. Check for malfunctioning EGR valve.
17. Check for brakes dragging.
18. Check for clutch slipping.
19. Check for low automatic transmission fluid.
20. Check for improper tire pressure.

OVERHEATING

1. Check for insufficient coolant.
2. Check for loose water pump belt.
3. Check for faulty thermostat.
4. Check for poor water pump performance.
5. Check for improper ignition timing.
6. Check for clogged or leaky radiator.
7. Check for improper engine oil grade.
8. Check for clogged oil filter.
9. Check for low oil level.
10. Check for poor oil pump performance.
11. Check for oil leak.
12. Check for dragging brakes.
13. Check for blown cylinder head gasket.

Intermittent Simulation

To reproduce the conditions creating an intermittent fault, use the following methods

1. Lightly vibrate component.
2. Heat component.
3. Wiggle or bend wiring harness.
4. Spray component with water mist.
5. Remove/apply vacuum source.

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for self-diagnostic codes. Use test results to identify a faulty component or circuit.