Engine Performance

It is important that the vehicle is operating at its optimum performance level to maintain fuel economy and the lowest emission levels. If the vehicle is not operating to these standards, refer to Diagnosis and Testing. The following procedures can assist in achieving the proper engine diagnosis:
1. Test cranking amperage draw (refer to Starting and Charging for the proper procedures).
2. Check the intake manifold bolts (refer to Intake Manifold for the proper specifications).
3. Perform cylinder compression test.
4. Clean or replace spark plugs as necessary. Adjust gap (refer to Powertrain Management for gap adjustment and torque).
5. Test resistance of spark plug cables (refer to Powertrain Management).
6. Inspect the primary wire. Test coil output voltage, primary and secondary resistance. Replace parts as necessary (refer to Powertrain Management and make necessary adjustment).
7. Test fuel pump for pressure (refer to Powertrain Management for the proper specifications).
8. Inspect air filter element (refer to Maintenance for the proper procedure).
9. Inspect crankcase ventilation system (refer to Maintenance for the proper procedure). For emission controls, refer to Powertrain Management Emission Controls System for service procedures.
10. Road test vehicle as a final test.