1G Bad ECU?

[Knuckles2.0]

ok this is a tuff one. my car was running like crap. i would pull to a stop sign, push in the clutch, and it would die. I thought it was the isc motor, but it reads 35 ohms so that should be good, i think. the tps reads bad resistance it sits at 4.0 ohms but doesn't go up while i move the throttle the resistance doesn't go up. so thats bad.

when i read the voltage coming from the ecu to the icp motor i get 12 volts on pins 2 and 5, and only fractions of a volt on the rest. On the tps connector i get 12 volt on one, 5 volts on one, and again only fractions of volts on the other two.

so here is what i think i have a bad TPS and a ecu with leaking caps or worse, and a good icp motor. does that sound right? does any one have any experience with this? sorry for missspelling ...

 

[4g63blinker]

Just pull you ecu out and look at it. It only takes a few minutes and then you would know for sure if there is a problem with the ecu.

 

[Robby Camero]

I have seen leaky caps that are VERY hard to tell if they are leaking because they sit so close to the board.

Take a q-tip, soak it in rubbing alcohal and dab it around the bottom of the caps and make the board wet with it. Then watch to see if any dark coloured liquid runs around. If so, yes you have leaky caps. They also smell funny, thats a give away too.

Or take a flash light and a magnifing glass and look real hard at the bottom of the caps.

Just saying this cause I once looked at an ecu carefully and missed two leaky caps. They arent always obvious to the eye.

 

[xxdprussxx]

i thought 35 ohms on a isc was bad? i thought it was like 28-30

 

[Knuckles2.0]

so 35 ohms is bad?

 

[4g63blinker]

'...4 different coils in the ISC that can go bad. If any of the values are GREATER than ~30 ohms (like in the kohm range), then you have a busted ISC and have to replace it.'

And you need to check the ISC when it is hot.

I just found this on a website:

http://www.myzero.com/engine/surge.html

 

[Morphius]

Originally posted by Robby Camero
I have seen leaky caps that are VERY hard to tell if they are leaking because they sit so close to the board.

Take a q-tip, soak it in rubbing alcohal and dab it around the bottom of the caps and make the board wet with it. Then watch to see if any dark coloured liquid runs around. If so, yes you have leaky caps. They also smell funny, thats a give away too.

Or take a flash light and a magnifing glass and look real hard at the bottom of the caps.

Just saying this cause I once looked at an ecu carefully and missed two leaky caps. They arent always obvious to the eye.

Very true. There can be issues with the ECU you can't readily see or may not be looking for.

A fellow DSM and coworker had a ECU go bad. Similiar issues as yours. He did have one cap that had just started to leak but it hadn't corroded the board. However, this wasn't the killer. Notice all the hundreds of tiny caps soldered the board? One of those had cracked and was none functional. Or it intermittantly would work. The reason he found it was due to a electronics technician with a good eye and was familiar with ECU repair.

So, check the electronics under the hood first. If you don't fix it there, then see if you can find a friend that you could swap ECU and see if that fixes it. If so, change the 3 caps that normally go bad. If your ECU still doesn't work, but your buddies does, send the ECU to one of the vendors that repairs ECU's.

 

[ericismyname]

you can just smell the board, if it smells way shitty there ya go.