While idling in my driveway, my 87 GT suddenly quit running. It has no spark from the coil to the distributor, although I have 12 volts at the connector to the coil, and 12 volts from the coil to the module. I replaced the incredibly corroded distributor last year...and now...bought a new coil, as it was a factory original, and also replaced the cap/rotor. Any suggestions as to where else to check for a problem ??
I replaced the incredibly corroded distributor last year...
The replacement distributor probably has a no-name ICM which has now possibly failed. Does the tach move when cranking over the engine?
Try disconnecting the electrical terminals at the distributor (including the pickup coil inside the distributor), check for corrosion, and then re-connect the terminals. Sometimes it's just a poor connection that causes an issue.
[This message has been edited by Patrick (edited 06-18-2025).]
Agree with Patrick... it's probably the ICM. This video might help... there's also an upgrade you can do to your distributor that adds a heat sink to it that'll make them last longer. This video is for a 2.5 distributor rebuild, but links and information are there to buy the heat sink, etc.
ICM. They are prone to heat failure and if the car was idling there's a good chance it was not getting enough cooling.
You can try this to see if it is the ICM. Buy a can of compressed air (Air Duster) like you use to blow stuff out of a keyboard or you PC motherboard. Turn it upside down and spray the ICM. You should get a stream of super cold liquid out of the nozzle. Sometimes this will restore the failed ICM for a short while.
This is just to check if the ICM is failed. It's not a guarantee that it will work but if it does, chances are the ICM is failing due to heat.
BTW, when replacing the ICM, make sure to use the right thermal paste. Do not use dielectric grease which some ICM suppliers pack with the ICM. You want good heat transfer, not insulation.
I would venture to say that the ICM on the Fiero 2.8 liter engines is probably the number one ignition item that fails. On a Fiero you have solid state electronics located not far from the hot crossover pipe. Only the highest quality ignition module like the AC Delco can survive in that environment. When I have encountered a faulty ignition the first thing done is to get out the tester and test the module. Some Autozone Stores advertise that they test ignition modules but when you go into the store looking for a test, you're greeted with WHAT Dah.....????
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Thanks for the feedback guys. I would also think the module is the problem...but I did have a new AC/Delco ignition module that I purchased awhile back just to have one in case AC/Delco stopped making them....I put it in...and still no spark.
you got fuel pressure or a fuel pump priming then? its gotta be spark or fuel/fuel map related if it shut off while idling and it wont restart and didnt make any bad noises beforehand. or you forgot to tighten the distributor and it turned enough to be an issue finally
