Is there a way to determine if either the Pickup Coil or the Ignition Control Module (ICM) may be causing a 'no spark' issue?

My '88 GT was running fine up until a few days ago. Then it began to start hard, and once it started, the tach jumped around until it warmed up.
Then yesterday on the way home from work, I stopped at the grocery store. When I tried to start it to get home, it would not fire up. The starter was turning over the engine fine.
I was just about ready to get some help from home, when it finally started. It ran ok on the way home, but would not re-start once I got it home.

I pulled the DuraLast cap and rotor off and returned them to AutoZone for new ones under warranty. I installed the new cap and rotor expecting it to start up.
It would not start up. I did a spark check, and I see now I am not getting spark at the plugs.

I believe some AutoZones are able to bench test an ICM if I bring it in loose off the distributor. So that is what I will probably do next.

Is there a way to determine if the Pickup Coil has failed?

I guess it may even be the Ignition Coil. I probably have a spare I can swap out for that.

Thank you for the help on this.

[This message has been edited by hdryder (edited 08-19-2014).]

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[This message has been edited by tshark (edited 09-08-2018).]

O'Reilly's can also test the ICM and they offer a lifetime guarantee on their new ones. My money would be on the ICM. It was very convenient of it to fail at home. Not a bad idea to test the new one while you're at the store.

I just took two ICMs up to AutoZone for a test on their Wells machine. The ICM taken off the '88 GT 'failed', and second I had on a spare distributor 'passed'.
So I installed the ICM that 'passed' on the '88 GT, but the engine did not fire.
I did notice that the tach did not move during cranking.
I can't remember if that is normal or not.

The tach should read about 400 RPM while cranking so you're still not getting a spark. I'd try swapping out the coil with your spare one.

Also check the connectors and the condition of the wires. Brittle and broken wires in the area of the coil are not unusual and can create strange problems.

Yesterday I swapped out the Ignition Coil, the small wire harness between Ignition Coil and Ignition Control Module (ICM), and the Electronic Control Module (ECM) from my '87 GT parts car.
Still no spark.
I have the spare distributor also from the '87 GT parts car, which appears to be a newer aftermarket unit. I will swap that out next.
Also, I will go through all the fuses.

Thank you for the help and ideas.

Make sure the connection between the pick-up coil and the ICM is good.
I had that happen on my 88GT and it turned out that the plug wasn`t connected good.
For some reason the plug on some pick-up coils and the little spade connector on some ICM`s are different shapes and they don`t always hook together good.

Also, make sure your distributor pick up coil looks like this (a little rust is OK...)



And not like this:

Check your pickup coil with an ohmeter and make sure you have some resistance. Also, check from the coil to ground to make sure it's not grounding to the distributor shaft.
Coil is easy to replace.

quote Originally posted by Bloozberry: Also, make sure your distributor pick up coil looks like this (a little rust is OK...) And not like this:

I've had a pickup coil that looked better than that first one fail, when ever the humidity was high and especially when it was raining the car would run like crap. test it, always test a part before replacing them, it can get very costly just throwing parts at a problem.

quote Originally posted by f85gtron: Check your pickup coil with an ohmeter and make sure you have some resistance. Also, check from the coil to ground to make sure it's not grounding to the distributor shaft. Coil is easy to replace.

with what he said /|\

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 08-22-2014).]

Just went through this on my '87 GT 2.8. Couple months ago cruising @ 75 the motor just shut off. Pulled over and replaced the ICM with the spare I carry (thanks guys on this forum :-) Car started right up and all was well. About 3 wks ago pulled in garage after work and shut off car. Next morning car wouldn't start. Changed ICM with new spare, no start. Did some testing, changed out for new coil - no start, more testing, pulled distributor and replaced pickup coil. Car started right up, but didn't mark rotor position prior to pulling distributor so timing was retarded. Pulled distributor and moved one tooth to advance timing. All is well. Don't be afraid of pulling distributor for this repair. But DO read the manual for the marking of the distributor and disassembly of the shaft components.

Before pulling the dist - Plug everything into your spare and attach a ground wire to it. Key on rotate the dist by hand and see if you get a spark. Then figure out which components work and which don't

ICM is cheap and easy. If that doesn't work it is almost always the distributor and we always seem to want to change that last. I went through everything but the distributor and should have done that first. Even if you mark it, the new one is likely to have different timing/position form the old. My new one was a good 20 degrees different so took a long time to get it timed to even start - also doubted it was the dist for a long time), but I knew I was getting spark and some combustion so persisted.

I found this posted earlier by PFF member fierosound. It looks a good step-by-step testing procedure for the ignition system and module.

http://easyautodiagnostics....-mounted-icm-tests-1

Thank you for all the help.

I found the problem that was causing the no-spark issue on the red '88 GT solid roof car.
On the connector for the Pickup Coil to the Ignition Control Module (ICM), the white female connector had pushed back so far into the plastic connector, that it was not making contact with the male connector of the ICM.

Once I pushed that female connector back into place in the plastic connector, and seeing that it was making complete contact with the plugged in ICM, it started right up with the good ICM off my '87 GT parts car, that had passed with the Wells tester at AutoZone earlier in the week.

Thanks again for the help.

quote Originally posted by hdryder: On the connector for the Pickup Coil to the Ignition Control Module (ICM), the white female connector had pushed back so far into the plastic connector, that it was not making contact with the male connector of the ICM.

I suspect it's often "simple" things like this which cause issues that are never properly diagnosed. Thanks for reporting what you found.

I had this same problem today. was driving along and all of a suddon BAM nothing. Had to be towed. Came here and found this topic. This place rocks. went to the store and bought one and wow!! its a whole diff car. The power had been not what I thot is should be and it ran rough. All that is gone now.