I need to have my ECM checked/tested. The distributor shot craps (copper winding blew out). New distributor installed and engine will not start. Checked engine codes and several point to faulty ECM. Any recommendations for getting ECM checked out?

 

If you post the engine, year, and the exact codes, I think you can get some good insight from people here. Once we know that information, I think there might be some tests in the Factory Service Manual that would potentially tell you if ECU has a problem or not.

When you say the distributor copper winding blew out, do you mean the ignition coil? Was the truck running prior to this?

 

When your truck was new, all the remote parts and the wiring were also new, so that in some diagnoses the process of elimination lead to "replace the ECM."

In fact, the ECM is very durable and only rarely the actual cause. After 20 (30?) years, all the other parts are much more likely to fail.

So don't get too excited when the list of 3-4 suggestions ends with "replace ECM."

 

Unless things have changed, ECMs didn’t have a procedure for testing the component itself.

The FSM gives you troubleshooting section where it lists all the possible causes for every drive ability issue , with essentially the most likely or easily tested first, and pretty much always ending with the ECU last. It’s last partly because of its unlikelihood of failure, but mostly because of it’s untestability.

Pull the ECM out and pop the lid. You can almost always smell and see an issue on a circuit board. I seriously doubt it went bad. I think more ECMs get injured while people are trying to test them than any other way. The fact that the ECM is logging codes makes me think it’s functioning properly.

 

It's a 94, 4x4, stick with a 22re. The motor is not the original one . One morning I started the truck, it ran for a second or two and died. I cranked on it a couple of times and it wouldn't hit.
It coded 24, 31, 14, and 31. (31) I replaced with a good MAS . 14 ?? The IGF... my Chilton book doesn't show where that is... or 24.. intake air temp. I need pictures where to find these on the truck to replace/test them.

 

I did pop the top on ECM and found nothing to cause concern. This process of eliminating is frustrating when you know stuff.. just not enough of the right stuff!🤪

 

Here, read this: https://www.yotatech.com/forums/f116...-quits-312747/

First, you don't have a "MAS." You have a Volume Air Flow (VAF) meter. Different technology.

What does code 24, code 31, and "runs then quits" have in common? The connector to the VAF. Use your multimeter to diagnose both your "good MAS" and the wiring feeding it. http://web.archive.org/web/201209071...33volumeai.pdf Ah, can't I just replace the bad part? The parts-cannon hasn't worked for you so far.

 

A pretty cool tool for doing a quick check is a spark tester. You can plug the coil wire into it and see how strong of a spark is being generated, if any.
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Just start working backwards from the distributer. Unfortunately, these days a lot more items can't be taken for granted, like wiring integrity. It's all on the table.
This is the one factory manual you should have.
1994 Toyota Truck EWD. It’s not just wiring diagrams. It’s SO much more if you sit down and go through it.

Did it ever run well with the new engine, or has the issue been there since the engine was installed? that's important info to have.