I took the 350 out of my '90 truck that was running like a top and put it in my '89 GTA. The truck was TBI with 5 speed trans. The car has a TPIS mini ram with stock injectors. Only the block and heads came from the truck. I'm scratchin a bald spot here. Everything checks out. 40 psi fuel pressure at the rails. fuel inj. all ohm at approx. 16 ohms. timing is correct at 6 degrees with est disconnected then reset computer and reconnected. timing seems to advance correctly. I used the distr. off the truck as well as the one for the car. I tried a new coil. i have verified/replaced plugs and wires. I have plugged/unplugged knock sens. the car will start everytime and idle rough and it runs like crap. I have a wb o2 that shows the afr good when it fires up then goes way lean. If I drive it like this and give it gas it richens for a second then way lean again. It is similar to a car that is running on about 3 1/2 cylinders. When I pull the plugs they are tan except for one and it is always a different one. I have an apyu chip and a stock chip as well as a refurbed ecm.

what do you guys think?

 

What about your TPS? is set at 0.45- 0.52 volts? If set low, lets say 0.30v, your car will run lean, if set high ex. 0.66v, car will run rich. Take a multimeter and check!

 

maybe it could be your EGR. i forget which one but if its either stuck open or closed, itle run like crap

 

tps checks out at .62 and the egr is gone. thanks for the tips. I talked to the mechanic and i'm taking the car there today. i'll post the diagnosis asap.