Preliminary Checkout

- Visually inspect the engine compartment to ensure all vacuum hoses and spark plug wires are properly and securely connected.

- Examine all wiring harnesses and connectors for damaged insulation, burned, overheated, damaged pins, loose or broken conditions. Check sensor shield connector.

- Be certain the battery is fully charged.

- All accessories should be OFF during diagnosis.

- When making measurements on a wiring harness, both a visual inspection and a continuity test should be performed. Inspect the connector pins for damage (corrosion, bent or spread pins, etc.) when directed to remove a connector.

- Spark timing adjustments are not possible.

- When making voltage checks a GROUND or LOW reading means any value within a range of 0 to 1 volt. Also VPWR or COIL PWR or HIGH readings mean any value that falls within a range of B+ to 2 volts less than B+.

- When using the spark plug firing indicator, place the grooved end as close as possible to the plug boot. Very weak or no flashing may be caused by a fouled plug.

- Spark timing will vary at idle due to feedback spark strategy used to control idle speed.

- Do not use an incandescent test lamp to check the CKP-, CKP+, PIP, IDM, or SPOUT circuits. The lamp will prevent the circuit from operating.