My 6.0L Topkick won't start and I think it could be the ignition module but hoping someone has more experience with these. I don't use the truck a lot but a few years ago I replaced the plugs, wires, distributor cap and rotor and it ran great. Now with the new track I'll use it as a water truck. Started up in June but was odd. It has first generation TBI fuel injection and normally would rev faster when first started and come down to idle after it warmed up. It started right up but didn't rev faster. Ran good though. A few days later it started right up but was missing and sputtering like it wasn't running on all cylinders. After about 5 minutes it was running normal again and had no problems with power or sputtering. Went to start it today and wouldn't fire. Distributor cap had corrosion and black spots on the contacts so I sanded it as well as the rotor. Still nothing. Looking online it appears it could be the ignition module or the coil but apparently there is also a pick-up coil in the distributor. Lots of corrosion in the distributor. I was also wondering if a fuel injected engine would have a wet exhaust if it wasn't firing or the ignition module also controls the fuel. Any guidance would be appreciated.
From the ones i have been around we replace the distributors alot and if they set around its worse.I have tryed to test them but that didnt show they were bad. I had one truck that would fire right up if i used a remote starter switch i ended up puting a starter button on it and useing it like that. They had to have the trucks now so i got parts fast Orielys if it was mine i would get something better.
I took the ignition control module out to have it tested since it was easy to remove. If it checks out might pull the whole distributor. I'm hoping I can get a mechanic friend to help me out with it.
I’d check your injectors also I’ve had several of the tbi injectors that would hang open and flood an engine
It's just an hei distributor system. Plenty on that on the web. If the pickup signal is missing, the injectors wont spray while cranking. I've had issues with the stator on top of the distributor cracking. That usually gives misfires, followed by dead truck. At key on, the injectors should emit a pulse of fuel, then pulse while cranking. If the injactors spray (pulse) while cranking, the coil is suspect. Had a POS MSD coil last two days. Contacts molded in held no tension.
It is not an HEI distributor.
My '95 C6500 with a 366 has a twin injector throttle body with an external coil HEI distributor. Do you have an epoxy (not oil filled) coil? If so, it's still a GM HEI ignition system.
Probably the same as yours. I thought the HEI used the odd looking distributor cap. It's pretty rusty and corroded in the distributor. Doing some more looking I think I should just replace the distributor. It's only $100 more than the ignition control module and includes the module. Parts in Canada are ridiculous compared to US prices. Couldn't find anyone who could test the ignition control module. I'm no expert on ignition systems and it's frustrating when no one is available to come out and help me.
Just an update. My mechanic friend came out and changed the distributor in under 15 minutes. Marked where everything was and put the new one the same. Didn't fire first try but waited a minute and tried again, gave about 1/4 throttle for a second and it started but wasn't running on all cylinders. One of the fuel injectors wasn't spraying fuel so he tapped it a couple times with a screwdriver and the engine came to life on all cylinders running about 1500 RPM. After a few minutes came down to about 1000 RPM and several minutes later came down to about 750/800 RPM. He said that's a good idle speed. I know when it's fully hot it will come down slightly more and the darn warning buzzer will go off because of low oil pressure. Touch the gas and it goes off. Anyway it seems the distributor was the problem and it's running properly now. It was a Chinese distributor but has a lifetime warranty. Best of all it was only a couple bucks more than just an aftermarket ignition control module and came with the ICM as well as cap and rotor. $146.00 so I'm very pleased with that. It's just a water truck on my land so didn't need to spend for OEM parts. He said I said I should start it and let it run for 10 minutes or so fairly often so I'll follow that advice. Thanks for helping to confirm it was something to do with the distributor! I was worried when it didn't fire the first time. Probably not enough fuel with only one injector working. Runs great now and I'll get some injector cleaner.