Chart C-4 Distributor Ignition (DI) System Check

*** UPDATED BY TSB 416525, DATED OCTOBER, 1994

Ignition System:

CIRCUIT DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
The battery should be fully charged prior to any tests.

1. Check for proper output from the distributor ignition system. The spark tester requires a minimum of 25,000 volts to fire. This check can be used in case of an ignition miss, because the system may provide enough voltage to run the engine but not enough to fire a spark plug under heavy load.
2. This test will separate the distributor cap, rotor and ignition wires from the ignition coil to help identify a secondary ignition system problem. It is necessary to unscrew the top terminal on the ST-125 spark tester for a proper fit in the distributor end of the coil wire.
3. This will determine if the proper available voltage exists in the primary ignition circuit.
4. A grounded coil circuit will cause the ignition fuse to open, and a no-start condition will occur.

DIAGNOSTIC AIDS
An ignition coil wire that is open or shorted to ground can cause a no start condition.