My nephews truck did a no start the other day, shut off in a parking lot and wouldn't start up. I owned it for several years and gave it to him a few months ago so I am pretty familiar with it and trying to help him fix it economically without throwing a bunch of not needed parts at it. Its an 85 model with 5.2 liter automatic. I pulled the #1 plug first and their is no spark. I started with the ignition control module since I had replaced it 4-5 years ago and it has a lifetime warranty. I took it in and they tested it and said it was good so I did not replace it. Then I looked toward the pickup coil in the distributor since it is original. The parts store says it cannot be tested. I had to pull the distributor and take it apart on a bench to replace the pickup coil, it was not a quick fix. I reinstalled the distibutor and still no spark. Several years ago I had put a high output ignition and coil on it, its by MSD. So I took another regular coil over their and tried it and still no spark to plug. The positive side of the coil is hot when checked with a test lite.It alsohas that little porcelain resistor on the firewall like the old mopars had and I tried jumping across it but did not replace it. I can't remember if these keep it from actually firing or not. I know it must be something simple and not a major engine problem since their is no spark. I can see right down in the carb and its getting fuel good. I am trying desperately to help him out since its his first vehicle and he has very little money to throw at it. What else could it be?? Any help would be appreciated. Thanks

 

No spark? I'd say if the coil is getting juice and not shorted out, it's the ECM, which you seem to have tested.

 

Could be as simple as a cap and rotor button.I once had a guy give me an old yota which he thought the timing chain was gone because of no spark.I put a new cap and rotor on it and drove the hell out of it then sold it for a profit.

 

Replace the ballast resisitor on the firewall. It will be a white bar with two or four wires on each side of the resisitor.

 

It was the high out put coil gone bad. I pulled it all out and replaced with a factory coil and bingo it started. Thanks for all the help!