TheRhino

So I'm looking at a 1990 with a 4.9l automatic trans 4 wheel drive. The guy said he replaced the starter, distributer, computer (ecu), plugs, new radiator, fuel and water pump and said it was running good then one day it wouldn't start for him. Would turn over tho. So then he said he burnt up the starter from trying and trying over and over again. So he replaced that and got a new cool and it ran fine then it died on him. It still turns over but he thinks it's something electrical. I've decided to ask here to get more possibilities of what it is not letting the truck start. Any help is appreciated thank you!! He also said there's no spark off the coil, so if that helps. Thanks again!

88xlt

Either the coil, the ignition module on the side of the distributor, or the PIP inside the distributor. I would test or replace them in that order. Some of these things were replaced, but I wouldn't trust that.

TheRhino

I was reading up on this ignition control module, now if this part isn't properly working it can be sending bad misreadings troughout the distributer and everything else that is fed to it correct

88xlt

I should have mentioned first of all, make sure you are getting juice up to the coil through one of the small wires that hooks onto the coil, with the ignition switch turned on.

TheRhino

Would I use a test light to see if there's anything going to it or a multimeter to see how much juice is coming from the wire?

88xlt

Well if the ignition module is bad you won't get fire through any part of the ignition when cranking the engine. Pulling the large coil wire off and holding it a little way from where it hooks in and cranking the engine over is a good way to check for spark.

It is very common for the ignition module to go dead on these early models(1991 and older) with the module mounted on the side of the distributor. Beings you have a complete won't start situation, you should be able to have the components tested. You need a special tool to remove the module from the side of the distributor, a skinny nose socket of sorts. Most deep sockets(nearly all) don't have a skinny enough nose to work.

88xlt

Either will work. I'm not sure how many volts you should get there, some ignition systems are set up to get the full 12 volts for starting and run on less than 12 volts so as not to burn things up. If you are getting some juice there I would assume things are okay.

TheRhino

Okay, I was reading a thing on how to check the ignition module. And with the coil already having no spark would replacing the ignition module possibly fix the problem ?

88xlt

YES. But I would try to test the ignition module first, a good quality one isn't cheap.

TheRhino

Alright thank you!!!