| ENGINE WILL NOT START | 1. Weak battery. | 1. Test battery. Charge or replace as necessary. Refer to Diagnosis and Testing . |
| 2. Corroded or loose battery connections. | 2. Clean and tighten battery connections. Apply a coat of light mineral grease to terminals. |
| 3. Faulty starter. | 3. Test starting system. Check for codes. (Refer to Appropriate Diagnostic Information) |
| 4. Faulty coil(s) or control unit. | 4. Test and replace as needed. (Refer to Appropriate Diagnostic Information) |
| 5. Incorrect spark plug gap. | 5. Set gap. Refer to Specifications . |
| 6. Contamination in fuel system. | 6. Clean system and replace fuel filter. |
| 7. Faulty fuel pump. | 7. Test fuel pump and replace as needed. (Refer to Appropriate Diagnostic Information) |
| 8. Incorrect engine timing. | 8. Check for a skipped timing belt/chain. |
| ENGINE STALLS OR IDLES ROUGH | 1. Idle speed too low. | 1. Test minimum air flow. (Refer to Appropriate Diagnostic Information) |
| 2. Incorrect fuel mixture. | 2. (Refer to Appropriate Diagnostic Information) |
| 3. Intake manifold leakage. | 3. Inspect intake manifold, manifold gasket, and vacuum hoses. |
| 4. Faulty ignition coil(s). | 4. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| 5. Contamination in Oil Control Valve (OCV). | 5. Remove OCV and inspect for contamination. Replace OCV if contaminated or sticking. |
| ENGINE LOSS OF POWER | 1. Dirty or incorrectly gapped plugs. | 1. Clean plugs and set gap. |
| 2. Contamination in fuel system. | 2. Clean system and replace fuel filter. |
| 3. Faulty fuel pump. | 3. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| 4. Incorrect valve timing. | 4. Correct valve timing. |
| 5. Leaking cylinder head gasket. | 5. Replace cylinder head gasket. |
| 6. Low compression. | 6. Test compression of each cylinder. |
| 7. Burned, warped, or pitted valves. | 7. Replace valves. |
| 8. Plugged or restricted exhaust system. | 8. Perform exhaust restriction test. Install new parts, as necessary. Refer to Diagnosis and Testing . |
| 9. Faulty ignition coil(s). | 9. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| ENGINE MISSES ON ACCELERATION | 1. Dirty or incorrectly gapped spark plugs. | 1. Clean spark plugs and set gap. |
| 2. Contamination in Fuel System. | 2. Clean fuel system and replace fuel filter. |
| 3. Burned, warped, or pitted valves. | 3. Replace valves. |
| 4. Faulty ignition coil(s). | 4. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| ENGINE MISSES AT HIGH SPEED | 1. Dirty or incorrect spark plug gap. | 1. Clean spark plugs and set gap. |
| 2. Faulty ignition coil(s). | 2. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| 3. Dirty fuel injector(s). | 3. Test and replace as necessary. (Refer to Appropriate Diagnostic Information) |
| 4. Contamination in fuel system. | 4. Clean system and replace fuel filter. |