Engine Performance

ENGINE PERFORMANCE
If a loss of performance is noticed, the timing belt or chain may have skipped one or two teeth. The camshaft and crankshaft timing should be checked. Refer to Timing Components.
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 General Information. The following procedures can assist in achieving the proper engine diagnosis.
1. Test cranking amperage draw.
2. Tighten the intake manifold bolts to specifications.
3. Perform cylinder compression pressure test.
4. Clean or replace spark plugs as necessary and adjust gap as specified in Powertrain Management. Tighten to specifications.
5. Test resistance of spark plug cables.
6. Test ignition coils primary and secondary resistance. Replace parts as necessary.
7. Test fuel pump for correct pressure.
8. The air filter elements should be replaced as specified.
9. Inspect crankcase ventilation system.
10. Inspect and adjust accessory belt drives.
11. Road test vehicle as a final test.