FBodyshuffle86

Alright guys, Im. New to this TPI and computer thing. I bought this 86 iroc back in October, the previous owner had swapped the original 305 TPI with a 350. I got the block number 10066036 off of it. The couple said it was a stock motor, they changed the prom and the injectors to 22lbs. I have verified the PROM is the correct one for a 350. Ive replaced the knock sensor, ESC, and ECM. the idle in PARK starts at 1500, then gradually goes to 1800-1900. It flutters between it. Ive tried to adjust the idle air control. The IAC is still good, had that checked out. The MAF sensor is still good as well. I have not a clue why or how to resolve this. I did get a code 53. That's why I replaced the ECM, so maybe just replacr the ALT. too? The bearings are going bad in it. I cant seem to find any vacuum leaks either. When I drop it into DRIVE the car's idle drops to 650-700. In NUETRAL it shoots back up and flutters.
SIDE NOTE: just did the IAC reset with the new ECM, got it down to 1400 in PARK, when I started it while I adjusted it, the motor kept dying, so I goosed it a bit to keep the motor alive, when I did that it had a steady idle at 500. Then I shut it off and plugged the IAC sensor back in and started it up. That's how I got it to drop 300-400 RPMS. am I not doing something right? Did I mess something up or is something just sticking at the throttle now?

Thanks for any help guys.

Tuned Performance

iTrader: (92)

With the code 53 still in the equation that could cause the idle issues. Have you cleaned all your grounds and positive lead at the starter. You may even have a fusable link at the starter that's corroded.

Tuned Performance

iTrader: (92)

If you adjust your min air speed you will need to reset the tps.
http://www.iroczone.com/2009/10/clea...rol-iac-valve/

http://www.iroczone.com/2009/10/adju...on-sensor-tps/