john36mc

I have a 1987 firebird tpi 305. I am having a problem with this motor not running in closed loop. This has been a project build . i have replaced 2 maf's,cts,tps, knock sensor. the otc scanner wont read the info like rpm,tps voltage,maf voltage or oxygen sensor. its stuck in open loop. any suggestions.
last week i had my friends newer scanner on it and i did see information. but it was there then it went away. it was intermittent .
i had a spare ecm and i put it in and all it will do is idle. if i give it gas it acts like a rev limiter .i did notice that with the otc hooked up it was reading kph 120 200 25 it was all over the place.
one last thing with my prom # hooked up to any scanner it keeps changing its all over the place too.
please help thanks john

john36mc

anyone?

tubbytownsend13

is ur normal computer mismatched with prom and main board being wrong? heard of this before with someone using a 350 computer on a 305 by accident. you may also have an intermittent ecm ground issue causing it to work just enough to keep running but not store anything. also, your aldl connector could be messed up wiring wise.

personally, my aldl connector had a cut in one of the wires just above the steering column and my buddys snap-on scanner wouldnt see anything. then it would, then it wouldnt. fixed it and no problems retrieving now

john36mc

do you know what color wire i can chase back to the ecm for problems or a lose conector at the adl. i am not going to lie this is a carb to tpi conversion. i have dont it all by my self with help fron you guys . again thanks and i will keep looking.
when i had the scanner on it the **** id # kept changing. i will have to also check all grounds.