So for thoes of you who dont remember the engine swap thread, a couple of months ago I bought a stealth with a spun bearing and droped a JDM in it. Since then I have had two check engine codes, TPS and inj. circut or somthing of that nature. We put an ECU in it that was known to be good and it took care of both codes as well as the bit of shifting and studdering issures it had. So today I got around to taking the "bad" ECU out and sure enough one of the capacitors started leaking. My first question is, can you use a lower voltage rated capacitor? The 3si wiki article mentions that it is ok to use a higher voltage capacitor, but said nothing of a lower. The reason I ask is because the local electronics place had the right ones, but they were rated to 25V, not 50. Everyone I talked to there seemed to think they would be fine because a car only runs on a 12V system. My second question is about different ECUs. Mine had an extra capacitor than the one shown on wiki, and several parts of the board were laid out different (it is a first gen). Why might this be?
Thanks much.

The TURBO 91/92s had different ECUs than the TURBO 93s. The 94's/95's are also different.

I can't exactly remember anymore what drivers where effected by the caps, but I do know if they don't get enough voltage, they won't work correctly if at all.

_________________
06 Blue EVO 9

I would try to find the 50 V capacitors. I'm sure there is a reason the Mitsu didn't use 16 V or 25 V capacitors they are not know for overegineering anything, except maybe the 20 lb A/C bracket.

_________________
'94 vr4- Now with extra slowness

Thanks for the info. Yea, I figured I would be better off to order the 50V, but was wondering if anyone knew for sure if it will make a difference to use the others. Well I checked the part # on my ecu just to make sure and it is the right one, and I got the new caps in....still doing the same thing. Does anyone know anything about ecu repair beyond just the caps? The board looked pretty good other than a little spot of corrosion under the leaky cap (which didnt extend out into any other leads)

Talk to Jon. He's an adopted W3SI member.

PM him at lethalvr4.

Best,

SJ

_________________


Racing is life. Everything else is just waiting.

http://umg.mn3s.org

http://ummo.boards.net

No reply yet. Any other way I might get ahold of him?

PM sent.

SJ

_________________


Racing is life. Everything else is just waiting.

http://umg.mn3s.org

http://ummo.boards.net

Do not downsize the voltage on the caps! They are designed to meet a specific rating and using a higher rating is not a problem. Lowering the rating and you could kill your ECU. Just because the voltage on the car is 12V doesn't mean everything electronic is 12V especially the ECU. These caps are extremely cheap. If you look online you can buy them dirt cheap, maybe .20 cents a piece. You will pay more for the shipping than you will for the caps. They can also be purchased on Ebay for like $6 a kit. I restore old pinball machines and video games so I'm always replacing old caps on monitors and boards. My car is parked for the winter so I may pull out the ECU and replace the caps. I just need to make sure I have enough spare caps laying around here.

Bunk

_________________
93 3000 GT VR4

Here is some more good info on installing caps.

Old worn out Caps
Two things may have / did occur. Time "Dried out" the electrolytic capacitors in your ECU making their capacitance reduce. Without the capacitors doing their job problems can occur. The other thing that occurs is that over the years the solder joints at connectors develop little cracks in the solder. These cracks reduce the surface area that the electricity can flow over and sometime stop it completely. The best way to fix this is to remove the old solder and resolder the connectors, preferably with 63/37 electronics solder (available at Radio Shack). This is called reflowing. Odds are your problems are from

_________________
93 3000 GT VR4