I have a computer controlled HEI remote coil set up from an 88 Camaro on my car.
The coil stopped producing spark. Nothing is getting to the distributor.

How do I tell if the coil has gone bad? I am trying to determine if the wiring from the computer is loose or if the coil is dead.

There are two 2 wire plugs that hook to the top of the coil. What kind of signal should I detect in them?

The car died on the highway at high speed after driving on a very bumpy dirt road. Would not restart.

The coil is made by Accel and has less than 300 miles on it.



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Jameel Qazi
#'s 67 SS
65 TPI / 700R4 El Camino

The two wires to the coil are just + and "tach" just like a regular HEI. If you conect to the "tach" side, you should read dwell. No dwell, distributor problem. (see below) If you have dwell, haul over to a REAL parts store, buy a spark tester. I like the ones that look like a spark plug with an alligator clip soldered to the side, but there are adjustable ones that have a fixed ground electrode and a movable positive electrode.

If the spark jumps an appropriate gap, the coil is good.

You might want to check the distributor itself. I've seen several small body HEI units that had a broken magnet in the trigger assembly. The fix is to order a new center shaft from GM. Not terribly expensive, considering. On my truck, I had a high-speed misfire that got worse and worse (lower speed) until the truck would stall at idle. Took about a year for complete failure, and I went NUTS trying to diagnose it.

Have you checked the resistance of the windings? That info should be in the service manual.

Thanks for the tips.

The coil is good. I took it out and put it in my 95 truck and it ran fine.

I will check the tach dwell thing. Spark tester is a good idea too.

I've got 12 volts coming into the tach on one wire and 6 on the other. These voltages are being passed to the distributor with a pig tail, but I don't know what the distributor is sending back to the car yet.

If there is no spark from the coil, then there has to be a problem up stream of the distributor, no?

I did have some problems with this distributor. The base plate would not stay on the shaft, so I epoxied it. Until then it would wobble and twist and not hold its timing. Maybe it got damaged during that time? But why no spark from the coil?

I tried a timing light on the main coil wire. That worked on my truck but not the car that's broken.

I tried removing a spark plug, grounding it to a header and turning the engine over. I could not see spark.

I stuck a spark plug in the coil wire, grounded it and turned the engine over. No spark. The spark should jump to the distributor cap if I'm close, right?

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Jameel Qazi
#'s 67 SS
65 TPI / 700R4 El Camino

It is not unheard of to fail the pickup coil in the HEI. Check this, too. And in the Tech Reference section on HEI, there is more troubleshooting info. Hei's are pretty simple on some ways. There is a coil, a pickup and a module. It is most likely one of those items, knowing that you have 12 volts going to the cap.

So I thought about this last night, and I realized that the distributor has to send a dwell signal back to the coil to make it fire, right?

That I have not checked yet. Given that the coil is known to be good, and I've got 12 volts from the car to the coil, my problem must be in the distributor, right?

I'll check the tech reference section.

Thanks again guys

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Jameel Qazi
#'s 67 SS
65 TPI / 700R4 El Camino

It was the module in the distributor. The guy at the parts store told me these things are sensitive to heat.

Now it all makes sense. Those dang headers are making the engine bay quite hot. Time to wrap the suckers.

Come to think of it, I have been having a hard time tuning this car. This could have been a big reason why.

Thanks for all your help guys. You saved me at least $100 in labor!

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Jameel Qazi
#'s 67 SS
65 TPI / 700R4 El Camino

[This message has been edited by jaqazi (edited 08-12-2002).]