1991 Laser ECU Question

tempfixit · #1 01-09-2008, 04:49 PM

91 Plumouth Laser, 2.0L Turbo, 5 Speed Manual Tranny, FWD.

Neighbors car. He installed new battery, when installing he hooked up the negative cable then the positive cable. (FYI) The car ran for about 5 minutes (while idling RPM's surged up and down.) and died. We tried carb cleaner in the throttle body and it would run as long as it a fuel to burn, so we knew it was a fuel problem and had spark.

DID the code check with a analog voltmeter and it show a constant 12 volt reading meaning ECU problem. Removed ECU and it smelled burnt. Took the cover off ECU found what I think is a capacitor had leaked and burnt the board. CAN THE ECU BE REPAIRED BEING THE BOARD IS BURNT????

If ECU cannot be rebuilt will a ECU from a 91-94 AWD with Turbo and manual trans work ??? IF so are there any changes that need to be done??

All advice is greatly appreciated.

SilvrEclipse · #2 01-09-2008, 04:59 PM

He hooked up the battery backwards and the motor cranked? Or did he switch the terminals first?

If the board actually has a burnt spot on it then your more than likely not going to be able to repair it. Does the spot interfere with any connections? You could try replacing the capacitor and see if it works.

It would be cheaper to buy a another ECU then to send it somewhere and have it fixed.

tempfixit · #3 01-09-2008, 05:34 PM

Thanks for quick response SilvrEclipse.

Let me clarify. He put the negative cable to negative post and positive cable to positive post BUT when he did this he attached the NEGATIVE CABLE then the Positive Cable instead of positive then negative to eliminate possible arching. (Could this have caused the capacitor damage?) There is actually residue on the ECU housing inside at the burnt location.

Can a non turbo ECU be repaired to work on a Turbo car and does it need to be a 91-94 ECU.

Thanks again for your help.

steviek · #4 01-09-2008, 06:31 PM

no you can't use a non turbo ecu. It must be from a first generation turbo car.
91-94 dont use a 90

steviek · #5 01-09-2008, 06:33 PM

also look at this for fixing the ecu
http://www.vfaq.com/mods/wayback/caps.htm

tempfixit · #6 01-09-2008, 07:54 PM

Thanks steviek for the information and link.

SilvrEclipse · #7 01-10-2008, 08:27 AM

O ok I understand now. I doubt that he fried anything doing that. I know your not suppose to but I have seen a few people do it with no harm.

Your suppose to replace the caps in those ECUs anyways to keep them from leaking. I would try to fix it first since it would be the cheapest option.

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