so about 6 hours ago my car ran fine. it took it in to be inspected, and it failed with flying colors on emissions (MA). HC and CO were not even close. HC was some 4 times the limit. I'm burning real rich!

the engine is HOT. i put the car into field mode and it refuses to get into closed loop even after 5 minutes. i'm stuck on open loop.

i went out and got a new ecm. traced iac, map, distributor, tps, air temp, and cts circuits to make sure they were over 20ohms. put new ecm in. immediately code 54 (failure in fuel pump relay or low fuel pump voltage) but i can hear fuel pump buzzin which makes no sense.

ignored code 54, went for a drive to warm engine. put engine in field mode and ecm shows it entered closed loop. YES! i drive off to get reinspected and fail again just like before. confused i go home, and check field mode again. stuck in open loop again. still code 54.

PLEASE PLEASE does anyone have any idea what the hell is going on?

-ian

 

what car (computer type) is it? my 95 lt1 wont change when I go to wot from cruise mode (open loop closed loop). I do know that my 94 lt1 z28 when I removed the o2 sensors ( no bungs in new headers) the car stayed in (I always mix them up) closed loop? Where ever it is when you start it or go to wot that is where it would stay with no o2s hooked up. So if you have a o2 sensor problem that will cause it to stay and not change over. sounds like you have a short in the heat circut alot of times they are tied into the fuel pump circuit for heater power. (Your code) But once again that holds true on a lt1 and not sure what you have. most likley will have same problem with a 730 ecm (speed density) 92 formula.