Engine Performance

NOTE: It is important that the vehicle is operating to its optimum performance level to maintain fuel economy and the lowest emission levels. If vehicle is not operating to these standards, refer to Engine Diagnosis outlined in this section. The following procedures can assist in achieving the proper engine diagnosis.

1. Test cranking amperage draw. Refer to Starting and Charging.
2. Check intake manifold bolt torque.
3. Perform cylinder compression test.
4. Clean or replace spark plugs as necessary and adjust gap. Tighten to specifications. Refer to Powertrain Management.
5. Test resistance of spark plug cables. Refer to Powertrain Management.
6. Inspect the primary wires. Test coil output voltage and primary resistance. Replace parts as necessary. Refer to Powertrain Management.
7. Test fuel pump for pressure. Refer to Powertrain Management.
8. The air filter elements should be replaced as specified.
9. Inspect crankcase ventilation system. Refer to Powertrain Management.
10. Road test vehicle as a final test.