Problems after ISC install

[nice97civic]

so here's the story. I had a bad ISC motor that I just replaced on my '95 GST. I removed the tbody elbow, and battery to perform the surgery. Removed bad motor, bolted down the new one, replaced battery and tbody elbow so now im ready to fire it up to see how she runs. Upon starting, the idle is back to normal right around ~750 with minor adjustment. However a problem arose with the throttle. When I blipped the throttle, there was a slight hesitation before the rpm's went up. Also, the fan's are on at idle, and for some reason there was smoke coming from underneath the dash on the passenger side. There are no unhooked wires, everything is back in the exact place it was before I replaced the motor. Anyone have any clue what the problem might be? Should I just let it idle for a while to see if it works itself out? I'm super confused as to what the problem is. Someone please help.

-Matt

EDIT: after restarting it I let it sit for a while and everything worked itself out. she's ready to play.

 

[ryanallan]

haha good to hear.
I hate when this type of thing happens. You get all stressed out for nothing !
Damb cars .

 

[nice97civic]

im actually a lil nervous right now because i just read another thread with similar symptoms and the burning smell turned out to be a fried ECU, so im really hoping thats not what happened to me but im not getting my hopes up

 

[jonnyp777]

That was probably my thread. Except my car flashed the CEL for about five seconds, then it went off, burning smell, then down the road my car wouldn't idle at all. If it's not dying everytime you let off the gas, then I think the ECU is fine, but you might wanna take off the carpet panels on the console and smell around down there, you never know. About your ISC, what tests did you do to determine that it was bad? Just the ohms readings or another one? I still need to make sure mine didn't go bad before I reconnected it. I really don't wanna fry the ECU I just bought for $180. That would suck.

 

[bling5tatus]

wow you got boned.... unless it's an eprom.... then even for 190, you still kinda got boned.

 

[jonnyp777]

I think what happened on my ECU, so steve thinks, is that the capasitor leaked and shorted the ISC driver and that burned up.
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How much should I have paid? I checked some junk yards and couldn't find any. I'm not gonna buy something like that off ebay to save like $80. And I'm sure steve is a good guy and would've done a good job, but even then, about $100, not including shipping both ways, and I would've had to wait for it to be shipped from CA to Chicago, have him fix it, and what for the ship back. Whereas I'm only waiting a couple days for mine from Kragen, which has a one year warrenty. So, how much would you have paid and where would you have gotten it? Please, enlighten me in case I need to buy one again sometime.

 

[voodoogsx]

I'd pull the ecu open it up and check for scorch marks...or at least look at the wiring around there....The extra precaution could save you a lot of bux...

-M

 

[nice97civic]

i actually got the isc motor for super cheap so i just replaced it because it didnt cost a lot. when i took the bad one out it was clearly fried up. my car doesnt stall after starting and i got down and smelled the ecu today and didnt smell anything weird (rotten eggs). i couldnt get the stupid plugs out of the ecu so i'll try again another day. i did however take out the radio and back there was a cluster#### of wires so its possible one of those shorted out or something, i dunno. still trying to re-organize the wires. hope all is good in there.

 

[jonnyp777]

If you do end up taking a look at the ECU, be careful with the screws to take off the cover. I stripped the head on one of mine and couldn't get it off. Steve said that you need a metric phillips screwdriver. So try that, or a flat head instead. What did your ISC look like? How could you tell it was fried? Maybe I'll take mine off before I get my car going again and take a look at it.

 

[nice97civic]

well first off i broke it cause i didnt realize the plastic and metal pieces were connected. the inside of the motor was brown and corroded. when i finally got the rest of it out, it was totally black and nasty. i can only assume it was black and nasty from being burnt up. if you have any question on how to get it out lemme know. it was fairly easy

 

[yokotabrat]

If the inside of the isc was all corroded, you might want to look into whether your FIAV is leaking cooling into the isc and throttle body. If it is, it'll just kill this isc and potentially your ecu if it hasn't already.

 

[nice97civic]

i guess i should rephrase what i said. it wasnt really corroded, just could tell it was old and needed replaced. there was no fluid inside the isc motor nor was there any in the tbody. but i'll check anyway just to make sure. thanks.

 

[nice97civic]

so after starting the car up today, idles great and everything seems fine. no more CEL so im happy. fastforward two hours after driving, i pull into a gas station and the CEL comes back on. wtf mate. help.

 

[nice97civic]

ok so i just took out my ecu to look at it and voila, fried. im not sure what the parts are but there are five black pieces that are right in a row on the right side of the ecu (looking from the non-plug side). anyone know what these pieces are?

 

[yokotabrat]

Those chips control various solenoids in the engine bay. Match up the one that's blown on your ecu with the list below and you'll know what it was controlling.

http://www.dsmtuners.com/forums/showthread.php?t=116585

 

[nice97civic]

looks like it was IC107, 108, 109. i think, though, that 107 caused the other two to fail because it happened after ISC replacement. is there any telling whether this will happen again after i replace the ECU? thanks for that link

 

[nice97civic]

well here is a picture of the mayhem. is it possible to replace these solenoids or do i have to invest in a new ecu. of course the more cost effective option is preferred, i'm just unsure of which route to take at this point.

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[yokotabrat]

The chips that are blown are replaceable, you just have to find someone that has them. They're very difficult to order. I imagine steve has these and could do the repair for you. I'd contact him to see what the most cost effective route would be to go.

Also, I haven't played with any 2g ecus, so I'm not sure what those chips control, however I'd assume it's the isc since that was what you replaced last. I'd check the resistance on your isc coils before you get another ecu, otherwise you're going to do the same damage to a repaired/new ecu. Hope this helps.

 

[nice97civic]

thanks for your help, i'll PM steve to see what i should do. i have the list of what those solenoids control and yes one of them is the isc, another is a/c i believe as well as something else. thanks again for the info

 

[nice97civic]

well, i have a dilemma. i need to know if it would be worth it to get this ecu socketed for dsmlink instead of buying a completely knew ecu?