93 LX 2.3L - Hesitation/Loss of power

What brand is the coil pack?

I hate to say it, but aftermarket electronics are junk for our cars these days. Not enough demand so the lowest bidder is who is making the dwindling supply of parts.

I have more faith in a 30 year old junkyard part than a new out of box part from many suppliers these days for our generation vehicles
All three that I have are NGK.
 
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The location of the coil packs on the 2.3L is pretty undesirable - right above the exhaust manifold. There is a heat shield that should be in place, although it is rather small and crappy. I would make sure that it is in place, though, because heat kills ignition coils. Creating a larger heat shield or relocating the coil packs may be a good idea if they continue to cause problems.
 
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Update:
The issue is not resolved. I let it sit a few days. Drove it today. It had been started not 2 minutes prior, so totally cold start. It had a total loss of engine power twice not long after pulling out of my driveway. It did this twice, in quick succession.
After that, it didn't happen anymore.
I suppose next I'll try testing those wires and also swapping the back coil pack with the front coil pack.

Could there possibly an issue with the pcm? It was replaced probably 10 years ago.

Also, here are pics of my heat shield.
 

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Update:
The issue is not resolved. I let it sit a few days. Drove it today. It had been started not 2 minutes prior, so totally cold start. It had a total loss of engine power twice not long after pulling out of my driveway. It did this twice, in quick succession.
After that, it didn't happen anymore.
I suppose next I'll try testing those wires and also swapping the back coil pack with the front coil pack.

Could there possibly an issue with the pcm? It was replaced probably 10 years ago.

Also, here are pics of my heat shield.

Definitely inspect your wiring. Clean up your connectors (compressed air, inspect the pins) and put them back together with some dielectric grease. This one is going to be a bit more difficult to find because it is intermittent, unfortunately, but a couple things you can do.

Start the car, and gently pull on the wires and connectors (gently, because these cars are old AF now!) and see if you get get it to hiccup. If you can, then you can narrow down your search.

Look for signs of corrosion or damage to the wiring harness - especially rodent damage if the car is sitting around much. Take the time to clean up your grounds and make sure they are well seated and not corroded.

A couple other quick points...

Are your engine mounts in good shape? This is low on the list and somewhat unlikely, but I have seen in the past where cars that have really bad engine mounts are pulling on the wire harnesses and can cause issues. Replacing the mounts is unlikely to fix your current problem, but if you do have excessive movement then you may want to resolve that after you fix this issue.

As far as the PCM - I think it is highly unlikely at this time. It would be pretty unusual for a PCM to hiccup for such a short time period. If the car was warming up and the ignition signal was being completely lost with no sign of any wiring or connection issues, then I would be more suspect of it, but since it happens when cold and only momentarily I think that replacing it at this point would simply be a shot in the dark.
 
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Definitely inspect your wiring. Clean up your connectors (compressed air, inspect the pins) and put them back together with some dielectric grease. This one is going to be a bit more difficult to find because it is intermittent, unfortunately, but a couple things you can do.

Start the car, and gently pull on the wires and connectors (gently, because these cars are old AF now!) and see if you get get it to hiccup. If you can, then you can narrow down your search.

Look for signs of corrosion or damage to the wiring harness - especially rodent damage if the car is sitting around much. Take the time to clean up your grounds and make sure they are well seated and not corroded.

A couple other quick points...

Are your engine mounts in good shape? This is low on the list and somewhat unlikely, but I have seen in the past where cars that have really bad engine mounts are pulling on the wire harnesses and can cause issues. Replacing the mounts is unlikely to fix your current problem, but if you do have excessive movement then you may want to resolve that after you fix this issue.

As far as the PCM - I think it is highly unlikely at this time. It would be pretty unusual for a PCM to hiccup for such a short time period. If the car was warming up and the ignition signal was being completely lost with no sign of any wiring or connection issues, then I would be more suspect of it, but since it happens when cold and only momentarily I think that replacing it at this point would simply be a shot in the dark.

Yesterday I started it up and gently wiggled and pulled on the wires of the icm, pcm, coil packs, and plug wires. No issues. No hiccups.
Engine mounts looked OK from what I could tell.

What ground points do I need to look at?

When I was doing the testing with the obd1 tester the other week, I noticed it would "hiccup" a couple times during the test. Not sure if that's normal or not.