Part 2 of my ecu problem

[OMFGeofffff]

Ok ecu gurus I have a predicament. I'm wondering why this wire is wired in between a cap and the "Coil "B2" for idle speed control motor" connector pin. Obviously my isc drivers are fried and that cap leaked but my car still runs(but with very bad idle). Is there something majorly wrong with my car somewhere because I've bought a replacement ecu with brand new chip coded for my vr4 and the car will not start with it. Also doesn't start with another noneprom ecu I have. Btw terry if you read this I'm trying to get my buddy with the known working ecu that worked in my car before to let me borrow it while I send these off to you.

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I made a little diagram for you incase this is easier to read and understand.

 

[Turbo4door1]

I can't help with most of your questions, but the wire is a jumper in place of a burnt/melted trace. Good sign that whichever ECU that is has been repaired before.

I toasted my ECU when my ISC shortet out. I sent it off to the ECMLink guys, and they fixed it up. I now have two "jumper wires" in place of damaged traces, but the ECU works great.

 

That wire isn't going to the cap. The one ISC trace goes right underneath the 47uF cap, and often gets eaten when the cap leaks. Someone bypassed the eaten trace with that wire. But, IMO they should have just avoided that area completely, as the board looks a little charred under there, and *might* even be what caused the ISC driver chips to burn out again. Personally, when replacing the ISC drivers I would remove the jumper, and install a new one that went the whole way to the ISC chip instead, and cut/remove the copper trace under the 47uF cap, to make sure it isn't hot anymore. The problem is that often the leaking caps start arcing and burning the board, turning it into a semi-conductive charcoal material, which can cause future problems if not avoided or removed. That's just my personal choice though.

 

[OMFGeofffff]

Ok. I just need someone that can test some ecu's and see what's wrong with them and then someone that's comfortable trying to repair the one that's burnt up.

 

[stevep]

I don't cut the pin 68 trace out unless it's damaged beyond repair. It was bad routing putting it under the cap but I try to restore everything to as original as I can. I've yet to see good replacement caps leak so the risk of leaving the trace there seems minimal.

Since both ISC drivers are fried I doubt the trace was responsible for the problem.

Because that board has been hacked on before it's likely going to need some TLC to make it reliable. That's not the same as just making it work.

Without pictures of the others it's hard to guess what maye be wrong with them. Have you made sure the EPROM chip was installed the right way? Tried swapping the EPROMS between ECUS?