ECU? Is it that?

[blackmirage]

Ok, When I purchased the car I was having alot of problems. You can reference the many posts about it I have created. Anywayz, I replaced the ECU with a used one from someone on the trader that had it in his basement, so I'm sure it wasnt rebuilt.. I just wanted to get one cheap to find out if thats what was causing the car not to run. I plugged it in, and away she went, running like a champ! Took it to the track several times, even layed down an 8.7 best in the 1/8th.. NOW, I went out the other day (this is only a track car so it just sits there on the non track days.) and went to start it, and it would start up just fine, but it would idle eratically and then die, all the while theres a LOUD clicking coming from the ECU. My questions are as follows:
1. is this the ecu caps leaking or something wrong with it?
2. is there something that could be possible shorting these ecu's out
3. is all this just because I went from one bad ecu to an ecu on its way out?
4. How much is a avg ecu rebuild and look over to make sure everything is in working order. As I know of a DSM Guru around here that can look at it, I just want to make sure I am not gonna get took.
I appreciate all your help in advance. Thanks.

Also, its a 90 eagle talon TSI 5 spd

 

[TwoLiterLaser]

1. is this the ecu caps leaking or something wrong with it?

That is usually what dies on the ECU so I would say probably.

2. is there something that could be possible shorting these ecu's out

Electrical defect from the factory, nothnig we can do about it other than the beefier caps

3. is all this just because I went from one bad ecu to an ecu on its way out?

Probably

4. How much is a avg ecu rebuild and look over to make sure everything is in working order. As I know of a DSM Guru around here that can look at it, I just want to make sure I am not gonna get took.

Call him and see what he charges, I would expect no more than $100.

I appreciate all your help in advance. Thanks.

You are welcome.

 

[90gsx16g]

Sorry for the old thread wake up, but i just burnt out my second ECU tonight in a 3 month period. I just installed a CD player a few days ago ( way better then my last one) and tonight i wired my Fuzz buster to my Cd player power and ground wires since my cig lighter doesnt work. I am wondering what would cause my ECU's to keep frying.

_My first ECu was an eprom and the caps blew( go figures they werent redone caps) Then the second ecu i got was NON-eprom and it looks like something right next to the ecu melted. _ thanks for any help or ideas

 

[architechnik]

We just went through an entire diagnosis of someone else after they have been frying theirs. Consider cleaning up your ground connections. Where is your stereo grounded - painted or cleaned surface?
He also replaced his MFI relay.

 

[90gsx16g]

I'm still learning as i go...but what is the MFi relay and where is it located?

 

[architechnik]

The MFI (Multiport Fuel Injector) Relay controls the fuel injectors and it involves one of the drivers (block things) on the ECU.
Here's a link that has a rough idea of what and where: http://www.dsmtuners.com/forums/newbie-forum/276071-mfi-fuel-pump-relay.html

The relay is just an in-between point where a low signal sent from the ECU can turn on a larger current for another device like a switch. Sometimes the repeat current is still too much for the little ecu to handle and often fries other parts.

Quick note: there is also an FP (fuel pump) relay right beside it and they usually work in tight conjunction, as more injectors means more fuel.

There's more pics and such here that go further into it: http://www.dsmtuners.com/forums/problem-diagnosis/263224-mfi-mpi-relay.html

 

[90gsx16g]

Here are some pics of where my ecu fried. Its right near the Cap's to the bottom left in one of the pics and to the top right in the other one.

 

[90gsx16g]

Looks like on of the tiny black squares melted then my cap kinda started to deform a little bit..hard to see in the pics. Loud ticking noise was coming from either the ecu or around it just befor my car died and i smelt the smell... of melting ecu.

 

[EagleTalonTim]

The little black things that you see fried are resistors. Just out of curiosity, what size fuse if going to your ECU?

 

[90gsx16g]

Thats a very good question... where would i locate the fuse for the ECU? under the hood or is it the one under the driver side panel? what position is it also?

 

[architechnik]

In those pictures, it actually looks like the capaictor started leaking and burnt everything around it. The content of those capacitors is just like the inside of a battery - bad news when it leaks. Considering that panel was on its side in the ECU, having damage toward only one side is understandable.

Now this is a prelim. diagnosis, as those pictures do not have much light and are fairly hazy. If the capacitors have damage, then it likely has nothing to do with the MFI relay or any of the drivers (long black blocks).

You should drop steve a pm with some better pics. He's the ECU guru around here. He socketed my ECU and I had him replace all those caps at the same time (I wanted to protect my investment).

 

[90gsx16g]

Alright so you think both the ecu's i had were just at the end of there life ? ### i moved the the cap a wee bit ( the one in the pic) and it looks like it started to leak thus causing yet again another short. What would cause them to short? oh and how do i go about gettin a hold of steve?

 

[awesome_asim187]

Also if you need another i have one from motoguysgarage.com they have them for $ 200 with a 12 month warranty.

 

[architechnik]

Steve is here on DSMTuners. In fact, steve is his name on here as well!
He works fast and he has a lot of experience in repairing ECU's. You should ask if this is something he can repair for much less than buying an entire new one.

The caps are a common problem in our ECU's and it's possible that they were never meant to last this long in the first place. Add all the moisture, vibrations, and general abuse we put our cars through... Well, have you ever had a computer that lasted over ten years of regular use?

 

[steve]

I can't tell if those four are all picture of the same ECU or not. It sure looks like one ECU.
The damage was caused by the C106 electrolytic capacitor leaking. It's too bad the caps weren't changed before it toasted that ECU.

The only fuse in this circuit is the 20A MPI fuse on the battery.

 

[90gsx16g]

Yeah i know the Cap's on our ecu's pretty much suck but this is my second ecu since i got the car in october, i'm gonna guess that both ecu's were crap and on there way out..

 

[steve]

Yeah i know the Cap's on our ecu's pretty much suck but this is my second ecu since i got the car in october, i'm gonna guess that both ecu's were crap and on there way out..

I guess I don't get your point or question. Without seeing both ECUs it's hard to say if there isn't anything else going on that is unusual and that is still a possibility.

The 47 and 100 uF caps used on all 1G ECUs were defective. Every single one of them will leak and cause problems. So unless they were replaced before they leaked or replaced by someone who knows what they are doing, the fact that they died isn't surprising.

 

[90gsx16g]

Well i know for sure that the other caps i had literally melted my Eprom ecu i had in there first, and you said the c106 on this one caused it to burn out... so if it is from the caps then i thats fine. I was just asking if there is anyway something electrical could cause them to short out aside from the manufacture defect they all come with. Judging by the pictures would you say my ecu is toast or is it repairable..?

 

[steve]

Judging by the pictures would you say my ecu is toast or is it repairable..?

I can't say for sure from the pictures. There is a lot I can't see.
In general as long as the circuit board isn't burned all the way through and none of the main chips is cracked or bubbled they can be repaired.

 

[90gsx16g]

Any ideas as to how much that would cost for a repair with new caps? Or how much to get it chipped?

 

[steve]

If you have business questions send me email. It's no longer a technical discussion.
I'm a wiseman not a vendor here and so the site rules are that we can't discuss business.