- Visually inspect the engine compartment to ensure that all vacuum lines and spark plug wires are properly routed and securely connected.
- Be certain that the battery is fully charged and that all accessories are OFF during the diagnosis.
A simple way to check for proper ignition system operation is the secondary spark test. If however, this test fails to show a spark, the individual components of the system must be tested. Refer to the different components in this section for their testing procedures.
Always turn the key OFF and isolate both ends of a circuit whenever testing for short or continuity.
Always disconnect solenoids and switches from the harness before measuring for continuity, resistance or energizing by way of a 12 volt source.
Before performing any component testing, check for and if necessary repair the following:
SECONDARY SPARK TEST
See Figure 1
The best way to perform this procedure is to use a spark tester (available at most automotive parts stores). Two types of spark testers are commonly available. The Neon Bulb type is connected to the spark plug wire and flashes with each ignition pulse. The Air Gap type must be adjusted to the individual spark plug gap specified for the engine. This type of tester allows the user to not only detect the presence of spark, but also the intensity (orange/yellow is weak, blue is strong).
- Disconnect a spark plug wire at the spark plug end.
- Connect the plug wire to the spark tester and ground the tester to an appropriate location on the engine.
- Crank the engine and check for spark at the tester.
- If spark exists at the tester, the ignition system is functioning properly.
- If spark does not exist at the wire, test the ignition coil, and other ignition system related components or wiring. Repair or replace components as necessary.