hello my name is Steve any suggestions are appreciated. I have an 89 TBI 305 I bought the car not running, got it running had no oil pressure rebuilt the engine now it has oil pressure but just like before it still will not idle without my foot on the throttle I've replaced just about every sensor or checked it. brand new distributor, cap, rotor, wires. but I feel like im missing something simple (or at least hope so).
possible thought I keep having is ecm? seems to be running pretty rich(black plugs) seems to run pretty solid when I have it running with throttle. set the timing twice now....I know a decent amount of automotive knowledge but not quite a guru. any questions or thoughts. thank you

 

Idle air control motor might be bad or gummed up.
Egr valve might be stuck open alittle.
Is the tps adjustable? Is so, then you need to get that set.
Make sure the vacuum hose to the map sensor is at the right port.

 

so many things it could be. if it is doing something exactly the same. you need to look at what parts did not get changed, or what parts got swapped over/replaced that need adjustment.

 

I'm having the same problem with a 91 Formula Firebird that the previous owner swapped out the original 305 with a 350. Car runs great when I have my foot on the gas, but I have to use starting fluid to get it started. It's TBI. As soon as I let my foot off the gas it dies. If you have any insight, I'd sure appreciate it.

 

Maybe the stop screw is adjusted improperly