faulty car!!! In need of desperate help!!!

bluecor · #1 (**permalink**) 10-01-04, 04:14 PM

I have a 1981 cadillac Seville and
I recently replaced the ECM as it was internally burnt, and it was causing the engine to backfire and missfire as well as stalling at idle and making the MPG panel go crazy with numbers

With the new ECM installed, the service engine soon light turns on and off at times as well as the coolant warning light, the engines idling rises very high but comes back to its normal idling level after a while. The MPG panel shows strange numbers at times such as " IC and 0.189 " . I have performed the diagnostic check-up on the ECC , but no trouble codes have appeared.

Please let me know if you have any solutions to this problem.
My email address is lugaseng@mweb.co.za

acerulz1 · #2 (**permalink**) 10-01-04, 11:11 PM

try disconnecting the battery for about 5 minutes and reconnect. did you have the battery disconnected when you changed the ECM? If not, this could have damaged the new ECM.

bluecor · #3 (**permalink**) 10-02-04, 04:06 AM

Quote:

Originally Posted by acerulz1

try disconnecting the battery for about 5 minutes and reconnect. did you have the battery disconnected when you changed the ECM? If not, this could have damaged the new ECM.

Re: I disconected the battery before i changed the ECM, the battery has been disconected for a month. The car had a similar problem before i changed the ECM, could it be faulty components in the electrical sytem, how can i test the ECM because its a rebuild.

acerulz1 · #4 (**permalink**) 10-03-04, 12:45 AM

there is no real way to test an ECM to see if it is faulty. The idle speed control motor (ISC) is something that can go bad. Sometimes they fall out of paremeter and cause a high idle. Could be a TPS sensor (throttle position sensor) too. When it used to stall, was it when you hit the throttle? As for the coolant light, that I couldn't even guess at. may want to take it to a shop so they can scan it and see if the sensor is reading proper temp. Could be a faulty sensor. May want to check body grounds too. I dont have the book for seville, only brougham, so I cannot give you any info on ground locations. But i know for a fact that a poor ground can cause some pretty funky stuff.