The Stovebolt Site Forums The Shop Area The Electrical Bay HEI electronic ignition question

Yesterday the truck started to labor and then died and will not start. It cranks and I smell gas but it won't start even with starter fluid.

I have one of Tom Langdon's mini HEI electronic ignitions. After a tow home I checked and I do not have spark. Is the flat coil that comes with the kit unique or can I use any regular 12V coil?

Does it sound like this is the part that failed or could it be something else like the distributor? The truck is 12V.

Thanks,

George

Yes, the coil is specific to the system. No, it's not likely tp be the problem. Check the primary and secondary circuits with an ohmmeter- - - -the primary should have about 1/2-3/4 ohm resistance and the secondary should have about 2,000 ohms or a little more. The most likely failure item is the module, followed by the pickup coil. The pickup coil should generate about 1/2 volt AC during cranking when disconnected from the module. There is no practical way to test a module without factory-specific test equipment, which some independent parts stores might have on hand.
Jerry

Thanks Jerry! My electrical skills are limited but I do have a multimeter that can check resistance. How exactly do I check the primary and secondary circuits? Sorry in advance (not a pun!)if that's a silly question. The previous owner installed the system.

George

The blade connectors that are used for the 12 Volts from the ignition switch and the wiring to the distributor housing are the primary circuit. Unplug any wiring and connect the ohmmeter to those to check the circuit that develops the magnetism as the module conducts. The big terminal that supplies the spark to the center of the distributor cap and the body of the coil is the secondary- - - -Set the ohmmeter to the "K ohms" scale and measure those connections for secondary resistance.
Jerry

Great, I'll check tomorrow in the light.

Couldn't wait. The primary circuit read 0.5 ohms (but it jumped around a lot). The secondary circuit read 14.88 on the K ohms scale. Is that 1488 ohms or 14,880 ohms)? What now?

Thanks,

George

That means you have a good coil. Yes, it's 14,880 ohms, about right for a secondary winding. In 55+ years of fixing virtually everything that rolls, floats, or flies, I think I've seen less than a dozen actual ignition coil failures. You need to concentrate on the internals of the distributor now, the pickup coil and the module. My money is on the module.
Jerry

IF The mini HEI is smaller then the GM factory HEI that module won't work. The is for the large HEI unit. You will probably have to contact Langdons to find out where to get parts.

The mini HEI distributor is based on a 1982-84 S-10 2.8L V6 distributor and uses a module and pickup coil for that application. Yes, it is a different item than the large-diameter GM HEI, but any local parts store should have all the electronic pieces in stock.
Jerry

Thanks guys. I just ordered one at NAPA and they say it will be in tomorrow.

I'm cooking with gas! What a great website.

Thanks guys,

George