i have a 99 1.8tQA with 140k. i have a cel and went to autozone to get it read and 3 autozones couldnt connect to my car, did a little research and found it may be a shot ecu. i replaced it with a matching ecu and now my car will start then turn off immediately.

Also: the car was idling rough with the old ecu, but still running, not alot of tach bounce but the car was very shaky in park and gear. it also sounds like there's air coming out of a hose on the driver side of the engine compartment.

 

with the old ECU, when you turn the key to the on position without starting the engine does the CEL come on? that is a sign the ECU is good. did you match the exact part number off the old ECU to the new one? do you have an aftermarket radio or the ABS airbag light light on (on the original ecu)

 

yes theres a cel with the old one, but there always was and now no one can read the codes anymore. same part number and i have an aftermarket radio but no abs or airbag light on the old ecu.

 

an aftermarket radio can disrupt the OBD2 port so that any scanner will not be able to communicate with the vehicle. some radios do, some dont. it seems greater then 50% of radios do disrupt the OBD port though.

 

thats very interesting, this may have been the first time i tried since i got the radio too...any idea on the car not starting with the new or old ecu? i can keep the car running if i give it gas but it stalls as soon as i stop

 

probably a massive leak somewhere. hoses get brittle and crack after 10 years. if you were able to read the codes you would be easily able to tell why it is happening. what part of CT are you in?

 

New Haven county, wallingford specifically...anywhere nearby?

 

bump.