broke91firebird

I bought this rusted 1991 Firebird 3.1L a few months back for $700. The P.O. said "it ran until the fuel pump went bad, then I parked it. All it needs to run is a new pump" After a bunch of digging it turns out that was a load of crap. I replaced the old rusted tank and non-working pump with the LS-6 tank and pump out of my other Firebird and now I have 45 PSI at the rail but it still wont run.
So far I have replaced 5 of the six spark plugs, checked the plug wire order multiple times, and replaced the Ignition module on the distributor. The car will run if gas is poured into the intake but only until it burns what you poured in.
The car has a nice strong spark but no Injector pulse. I hooked up a professional scan tool up tot eh car and the ECM sees no RPM while cranking. The car currently has code 39? (bad ICM signal).
Also the only light that comes on with the key on the dash is the "Inf RES" airbag light.
I know that somewhere along the line the computer was replaced since it has a sticker that reads "Use prom and cover from original ECM" on it. Any help or ideas would be appreciated.

fasteddi

iTrader: (2)

Make sure that your wired connections are good on the ICM at the dizzy. Also did you put down a good layer of dielectric grease under the ICM when you replaced it?

broke91firebird

The connectors appeared to be clean and were tight when I clipped them on. Ya i put a good layer around the entire bottom of the ICM.

fasteddi

iTrader: (2)

Check your ecm. Make sure that all the connections are nice and tight. Did you get the ICM brand new?

The only thing that tells your ecm that your engine is turning over is the ICM reference pulse. Did the rotor and such look ok under the Cap on the dizzy?

Does the tach work at all? Thats a different wire coming off the ICM. If your tach works then you have a wireing issue somewhere or a flaky ECM... just my guess.

So no spark reference then no rpms on the ecm and no injector pulse.

broke91firebird

The connections appeared tight but I didn't play with them much as I still had the battery hooked up. The cap and Rotor look new, there is no build up on the brass at all. No the tach doesn't read and on the scan tool none of the censors would respond to input. the Throttle position stayed the same regardless of where the accelerator was and it couldn't see the neutral safety switch at all.

fasteddi

iTrader: (2)

Check over all the wire harnesses arround the dizzy. There is a main one near the engine that loops arround the engine. mabey something got toasted there and cut or burnt a few wires.

broke91firebird

Well i got the convertible nicknamed Phoenix running! After visually inspecting all the wires near the distributor and finding all in good shape, I tried swapping on the computer out of my hard top. At that point I had communication but still no spark until i put the original PROM back in.
Now it runs but there is still no real communication between the ECM and the TPS. The scanner is seeing the ECM reading 92% open throttle even with the TPS physically unplugged. YAY now I have to find a wire short between the two.

Thank you everyone for the help!