Chart C-4A, Ignition System Check (Remote Coil)
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- Checks for proper output from the ignition system. The spark tester requires a minimum of 25,000 volts to fire. This test can be used to diagnose an ignition miss. The system may provide adequate spark to run engine, but not enough to fire spark plug under heavy load. 1A) If spark occurs with EST disconnected, pick-up coil output is too low for EST operation.
- A spark indicates problem is a faulty distributor cap or rotor.
- Normally there should be battery voltage at "+" terminal. Low voltage would indicate an open or high resistance circuit from distributor to coil or ignition switch.
- Checks for a shorted module or grounded circuit from ignition coil to module. The distributor module should be turned off so normal voltage will be 12 volts. If the module is turned on, the voltage will drop but should be above one volt. Failure of this test can cause ignition coil to fail due to excessive heat. With an open ignition coil primary winding, a small amount of voltage will leak through the module from the "Bat." terminal to the tachometer terminal.
- Checks for an open module or circuit. With 12 volts applied to the module "P" terminal, module should turn on and voltage should drop to 7-9 volts.
- This should turn module off and cause a spark. If no spark occurs, the fault is most likely in ignition coil.