ECU problems

[Lancer99]

Well I finally figure out what was wrong with my 1991 Eclipse gsx. The ECU took a dump, how do I know I swapped ecu's with my vr4 and it fired right up. So I had my father in law replaced the caps and cleaned it up a bit. Anyways a week later he gave it back to me and said that it had a lot of damage from whatever leaked. So I put it in and nothing, wouldn't fire up. So I bought another non eprom ECU from a trusted board member and he's ecu was mint and new caps and still nothing but my VR4's eprom ecu which is not in good condition fires it up. O by the way the original ecu is a non eprom. WTF is going on with this damn car! /ubbthreads/images/graemlins/banghead.gif

 

[JCorbo25]

It could be a 1990 ECU you purchased and the pins are slightly different.

Can you test the ECU you purchased in your GVR4?

 

[Lancer99]

No its been down for 3 years. The guy I bought it from said its a 94 ecu, and I trust him on that because I bought several parts from him

 

[Lancer99]

Anyone?

 

[grocery_getter]

Take over head picture of the boards of all 3 ecu. Label them which is the original gsx ecu, the vr4 ecu and the one that you bought off a forum member and put them up here.

 

[Lancer99]

I don't have the best camera but here you go.
Heres all three together, the Original is on the right, my VR-4's in the middle, and the 94 auto that I bought on the left


Closer view of the original that my father in law replaced the caps (non eprom)


Closer view of my VR-4 notice that it has more damage than the original if you can see.(eprom)


Closer view of the 94 auto ecu, cleanest of them all (non eprom)

 

[MuffinMan7580]

Quoting JCorbo25:
It could be a 1990 ECU you purchased and the pins are slightly different.


The car would still fire up and rev.

 

[grocery_getter]

Here's what you have:

MD165529 - 6576M (The ecu that comes from your car)
This is 6/90-6/92 Federal AT ecu

MD165810 - 7378E
This is GVR4 federal MT ecu

MD166262 - 6578M
This is 6/90-6/92 federal MT ecu

None of your ecu is a 1990 style. They're all the proper 91-94 style as far as pin arrangement is concerned.

Both your original ecu and the ecu that you purcahsed had the caps replaced, while the GVR4 ecu still has original caps. Perhaps there are electrical trace on ecu board that was damaged and overlooked during caps replacements.

 

[Lancer99]

My Eclipse is a 1991. The original ECU number is the MD166262. The automatic one is what I bought. Neither of the non eproms work, but the Eprom from the my VR-4 works fine and no check engine light. Heres my vin# if it gives more info about the car #4A3CT64U7ME121263

 

[grocery_getter]

Both your original ecu and the ecu that you purcahsed had the caps replaced, while the GVR4 ecu still has original caps. Perhaps there are electrical trace on ecu board that was damaged and overlooked during caps replacements.

 

[Lancer99]

Sorry I kind of read your other post fast and thought you missed understood and thought I bought a 1990 ecu. Well I'm going to contact the seller and ask him if he knows that if the ecu was working in his car after the caps were replaced. But thanks for all the info you gave me and I'm going to try and find another ecu locally so I can try it before I buy it.

 

[grocery_getter]

Since the untouched virgin GVR4 ecu works on your car, there is nothing wrong with the car. The troubleshooting shouldn't be focused on the car instead the focus should be on the 2 ecus and what might be wrong with them. Why don't you stick the other 2 ecus in your gvr4 and see if it will start and run the gvr4.

edit:
Just saw on your sig line that the Gvr4 is a roller.

When you put the 2 non working ecus in the 91 gsx, and you turn the key to the ON position (you don't need to start the engine, just the "ON" position.), did the check engine light turns on and then turns off again after a couple seconds afterwards? That is the boot check that the ecu goes thru. If it turns the CEL on but doesn't turn it off or if the CEL doesn't even turn on at all, then the ecu just fails a boot-up check.

 

[Lancer99]

I havent checked that check engine part yet. I know I saw the check engine light pop on but never really paid attention to it afterwards. I'll try that tonight and see what happens.

 

[Lancer99]

Well I got a chance yesterday to swap out ecu's and both non eprom ecu's the check engine light did not pop on but the eprom it came on then off, just like it should. So i take it then the others are junk?

 

[grocery_getter]

Yes. It is probably repairable, depending on what the problem is.

 

[Lancer99]

Who and where can I get it repaired? Is it even worth it on a non eprom?

 

[ktmrider]

^^ stevep for major repair work, Terry Posten for minor repair/re-capping.

 

[stevep]

He has to drive pretty much past me when he commutes but I don't fix ECUs anymore.

 

[Lancer99]

I bought another non eprom that works. The one I returned and the other im going to send it out to have it all fixed up as a spare.