Look at my ECU circuit board, what is this brown crap by capacitors?

[awdtalon4451]

Hey all I've been fighting a lean issue after i installed my 2g MAF on tuesday.
When i pulled out the ECU it had been rebuilt last year by auto computer exchange according to the stickers on it. Busted the ECU open go find this.

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[snowborder714]

They leaked. They need to be removed, have the affected areas cleaned up, and new caps put in.
http://www.dsmlink.com/wiki/corrosion03

 

[awdtalon4451]

They leaked. They need to be removed, have the affected areas cleaned up, and new caps put in.
http://www.dsmlink.com/wiki/corrosion03

Could it be the cause of my extreme lean issue?

 

[Firsts tuner]

Have they leaked or is that just flux around the solder joint? I thought the capacitors popped on the top and oozed down. I am not by far an expert though.

 

[eclipsyco]

It's the only place where you have that? usually caps leak form the top but not always if they are the OE caps i'dont think mitsu people would do such a nasty work on it plus they use electrical coating after that to meake sure it last for a while i would say remove, check, clean and install new one.
And no that's not the reason of the lean condition!

 

[1qkfwd]

First off thats not a factory cap. The factory caps sit so close to the board that you cant see daylight between them and the board. The factory cap for that spot are a bit fatter to. Thats just a dirty solder joint.

Hey all I've been fighting a lean issue after i installed my 2g MAF on tuesday.

Might wanna look more into this. Get your Ecmlink installed and set it up for your 2G maf. Go from there.

 

[PieEyedPiper]

I posted my response in your other thread.
http://www.dsmtuners.com/forums/newbie-forum/449492-8-7-volts-fuel-pump-why-2.html

I agree with ARFWD, this may not be the cause of your problem. But there is no doubt about it, that cap is bulged.

 

[awdtalon4451]

First off I wanna thank everyone for your time and help with this nightmare I've been going through.

It's the only place where you have that? usually caps leak form the top but not always if they are the OE caps i'dont think mitsu people would do such a nasty work on it plus they use electrical coating after that to meake sure it last for a while i would say remove, check, clean and install new one.
And no that's not the reason of the lean condition!

Yes its the only one that was leaking. At least fron what i can visually see. It seems to be coming out from the bottom edge of the cap. Ill see if i can get a pic of it.

First off thats not a factory cap. The factory caps sit so close to the board that you cant see daylight between them and the board. The factory cap for that spot are a bit fatter to. Thats just a dirty solder joint.



Might wanna look more into this. Get your Ecmlink installed and set it up for your 2G maf. Go from there.

I've been installing my ecmlink since my last post and I've switched it to 2G MAF and the difference was night and day...then my computer died :/ I've yet to set my global deadtime or anything for that matter.

I posted my response in your other thread.
http://www.dsmtuners.com/forums/newbie-forum/449492-8-7-volts-fuel-pump-why-2.html

I agree with ARFWD, this may not be the cause of your problem. But there is no doubt about it, that cap is bulged.

PieEyed I'm just curious as to what would cause this being the ECU was rebuilt less than a year ago. Was it something i caused or just poor workmanship?

 

[DSM1G90]

Looks like an overdose of flux from not putting the cap more close to the board on replacement.

That's a major fail in a soldering job-no flux should be exposed on the face of the circuit board like that. See how the other two caps are snug fit against the board?

And the top of the cap isn't all swollen up and the tri cuts on top aren't split open- why the 'triad' cut on top of the cap does .. to relieve the pressure when the do swell. That's their "safety valve' of sorts. See one of those cuts split open, it's a gone cap for certain.

 

[eclipsyco]

What kills circuit boards is cold solder specially in our cars which are old... Look into your ECU for something that look like this..

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Sometimes they are hard to spot...

 

[apprentice101]

That's not the cap leaking, that's definitely flux and a bad solder joint. When the caps leak its a lighter colored paste usually coming out the top, sometimes at the bottom edge between the plastic bottom and the aluminun side. Some guys actually stick the cap leads in a tube of flux and then solder the component. Caps are cheap you can always re do it especially If its already out.

 

[PieEyedPiper]

PieEyed I'm just curious as to what would cause this being the ECU was rebuilt less than a year ago. Was it something i caused or just poor workmanship?

I'm sorry, I can't truly answer that for you. It is not my opinion that some sloppy flux killed the component. Caps go bad for a variety of reasons, and it usually comes down to quality. I wouldn't really pay it much mind. Just one more thing to fix. Everything has a MTBF [Mean Time Between Failure] especially if it's from China...or Illinois. <--- catch that? tee hee

And the top of the cap isn't all swollen up and the tri cuts on top aren't split open- why the 'triad' cut on top of the cap does .. to relieve the pressure when the do swell. That's their "safety valve' of sorts. See one of those cuts split open, it's a gone cap for certain.

I disagree. Granted, I do not have the part in my hand but the cap appears bulged to me. In a perfect world the vents will open. Out of the 1000's I've replaced, I'd say I've replaced less than 20. It might have something to do with the quality, environment or even the manufacturing batch..

A cap can be bad but look entirely perfect, no leaks, no open vents, no bulges at all.

I don't want to derail this further, though, as I've already given my suggestion.