System Quick Check (Engine Will Not Start)
Pretest condition: engine will not startIf the engine does not start, the fundamental step in trouble shooting the ignition system is to determine whether or not the system is creating any kind of spark at the spark plug. If a spark is present, it is the ignition systems efficiency/accuracy or another system's function that is in question. If no spark is present, more detailed testing of wiring, connections, battery or individual components is needed.
NOTE: Battery must be fully charged and terminals must be in good condition for all tests.
1. To check for spark, turn ignition OFF.
2. Remove a spark plug wire.
3. Connect it to a good (preferably new) spark plug and hold the outer electrode, with insulated pliers, to ground.
WARNING: Use insulated pliers to test spark plug, other equipment may cause bodily harm or death.
4. Have an assistant crank the engine. Look for spark in the plug gap.
a. If a bright blue spark is available, ignition system is healthy, fault may lie in the fuel, computerized engine control or other related system. End of test.
b. A yellow/orange spark is weaker and indicates that ignition system is not operating at peak efficiency. Check such components as the coil/plug wires, cap and rotor. If no fault can be found, check the rest of the ignition system components in this section. If no fault found, refer to COMPUTERS AND CONTROL SYSTEMS for procedures on testing any computer controlled ignition components.
c. If there is no spark, check the wiring to ignition coil[1]. Also check the ignition switch, ignition coil, Hall effect sender and power output stage. If no fault can be found, check the rest of the ignition system components in this section. If no fault found, refer to COMPUTERS AND CONTROL SYSTEMS for procedures on testing any computer controlled ignition components.
5. For additional trouble shooting information See IGNITION SYSTEM/TESTING AND INSPECTION/PROCEDURES/DIAGNOSIS BY SYMPTOM
Diagnosis By Symptom
6. Reconnect spark plug wire.
[1] When the ignition is in the ON position, there should be approx. 12 volts available at the ingition coil.