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ecu shutting off?

so i was driving around last night and i pushed my car to WOT and randomly the ecu clicked off and my car stopped getting fuel. all indicator lights came on and there was no power. i took the car out of gear, revved it, and put it back in gear. i could drive for about 30 seconds before it happened again. i have my glove box off for cleaning, so i disconnected the ecu, check out the harnesses, and reconnected it. problem solved. then today, the same thing happened. the ecu appears to be fine and the caps do not look like they have damage to them. suggestions?
 

4orced4door

Moderator
Joined
Jul 19, 2002
Messages
9,846
Location
Raleigh, NC
Have the caps been replaced? You really can't tell if they are damaged or not without pulling them off. Do they smell bad?

If your caps haven't been replaced, change them whether you think they are bad or not.
 

<- is stupid...i was looking at the wrong electrical unit. i took what is actually the ECU out and noticed first off the black stains on the inside of the ECU cover. next, 3 components are completely fried. my guess is when my alternator blew, so did these. they aren't caps, but i think it can be repaired. can anyone help with this? the are long and thin black components located at the top of the ECU if the harnesses are on the left.
 

Hertz

Staff member
Joined
Jul 29, 2002
Messages
13,501
Location
Chicago, IL
ecucapmarks.jpg
 

right where it says "100uF" is where the damage is, and below that. do i need to replace it? i would rather not mess with it if i can just replace the entire unit. anyone have one kicking around? averages prices?
 

You can swap it for another one from an ECU remanufacturer, $300-$650. But you'll probably just get another one that had acid damage just like yours, but has been fixed. I see you've only been a member of this board for 3 months, so I won't yell at you too loud for not replacing the caps as soon as you got the car. I'll fix the ECU for free if you ship it to Florida. Or, I'll give you $100 for it so I can fix it to have another spare. Its your choice.
Jeff O.
#1886/2000
 

gvr4ever

Well-known member
Joined
Aug 6, 2002
Messages
6,232
Location
central Indiana
It's clear your ECU needs attention anyway, but have you checked your battery?

I guess it is the shock of all the mad powwa, but at least once a year or so, my battery connections come loose on me.

Just a few months ago, my car was shutting off and turning back on. I knew my caps were replaced, so I checked the battery first thing. Yup, the negative likes to get loose alot. I had the same problem with my Talon too.

I've learned to just check the connection every time I do a oil change.

Anyone else get this?
 

I see now, I misunderstood, your's is damaged where the lettering that says "100uF" is, not where the 100uF is. That is the fuel injector driver circuitry.
I'll still buy it. Original GVR-4 ECU's are hard to come by. Let me know.
Or. is it something like this?:

url]

That is one of the ISC drivers smoked in that picture. This is usually caused eitehr by 1)a shorted ISC, 2) acid under the 47uF cap, or 3)water in the ISC from the FIAC leaking.
 

thanks for the offer jeff. i found a few on dsmtrader.com that i might pick up for under $100 or i might get one from my local evo/galant rally team if they have a spare. if i can't get one, i will contact you. the only problem is that the caps are fine, its other components on the ecu, so i don't know if its fixable.

battery is new, firmly attached, and not the cause of my problems.
 

that is where it is burned. i ordered a new ecu, should be here soon.

jeff, you can have mine if you'd like. send me a PM if you're still interested.
 

turboflanagan

Well-known member
Joined
Mar 5, 2001
Messages
2,572
Location
Peachtree Corners, Georgia, USA
Pay very close attention to what Jeff just said. If it was 1 or 3 of what he said, your Problem will remain even though you have a new computer. Then your new computer becomes trash like your old one. Check the ISC for a short or water in it. Do a search for ISC and you should find coverage of these problems.
 

i recieved my new ecu today and its NOT THE RIGHT ONE!! i specifically told the seller turbo awd. anyway, it is missing the large chips on the right side of the picture above and some other stuff, i'm not sure where it is from. most likely a non-turbo. i need one, can anyone get me one asap?
 

Chris,
You can tell if it is for a Turbo car or not by whether it has that large, elevated PC board in the bottom right corner, with the black donut in the middle. That is the knock sensor board. If you don't have the chip in the top right corner, that just means it is a non-EPROM board, so you can't play with any of my free chips. What is the actual model and part numbers on the label? And, does the number stamped in black on the white connectors match the last 4 digits of the model number? From the info on the VAQ you should be able to tell exactly what year and type car it came from.
By the way, I just Paypal'd you for your old ECU.
 

year: 1991
part number: MD165810
model number: E2T37378

the numbers on the connectors match the model number. this ecu looks exactly like the one pictured above, so i'm guessing its an eprom board. i'll send it out to you, i just need to know what will work on my car. i've recieved two other ecu's and niether has worked, the car idles at 300 rpm and bucks.
 

i have 2 ecu's. both are missing the top most 2 chips on the right side, and one is missing a white board under the CAPS. i don't have an afc to help with fuel flow, so what do i do? i thought that 91-94 turbo awd ecu's will work perfectly. was i wrong?
 

Chris,
The number you posted is correct for a GVR-4, but I meant the numbers on the replacement ECU's you have gotten. If the one is missing the one white board, it may not even be a '91-'94 ECU. I need to cross the MD numbers in CAPS to be sure.
If you don't have an AFC, the idle *should* improve as the ECU raises the lower fuel trim. GVR-4's don't have the lower honeycomb in the MAS, so without the correct ECU you will run leaner at idle. Anyone have a lower honeycomb they can send him if it doesn't improve?
 

i put back in the ecu i bought and revved it until the idle started to improve, but then the ecu started smoking and my ISC caps were blown again. you mentioned something about a shorted ISC? please help me troubleshoot this, i just wasted a $90 ecu...
 

I warned you......
http://dmtalon.v8eaters.com/ISC.html
There were also some posts on here about 6 months ago about the problem with the gasket in the FAIC section of the throttle body leaking and the coolant getting into the ISC.
Its real easy to pull the ISC out and look for moisture.
 
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