Fiero Throttle Body Help

I have a manual 1986 Fiero 2m4 2.5 L TBI, we are having some trouble with the Throttle Body, the car starts very good, and it also idles fine, runs fine, all gears work.

Heres the problem, when you lightly tap on the gas (lets say in neutral) to around 1500 rpm, it spits and sputters, when this occurs the rpm drop and moves around violently under 1000, sometimes it the engine dies and sometimes the engine regains its idle. But when you hit the gas hard it revs and goes back into idle just like it normally should do. when the car is in gear, it does the same thing, stopping at a red light means there is a chance of starting it again.

we are convinced that something is wrong with the Throttle Body Injection or its sub-components. Please give me some feedback on this, it would be very much appreciated, thanks.

-nick

Two things to check: one is the throttle position sensor. It is simply a variable resistor that changes its resistance according to the position of the throttle. Checking it as such is simple. Using an ohmmeter, move the lever, allowing the meter to indicate the readings. An analog unit is better here, as the problem will likely appear as a resistance that jumps around, instead of operating smoothly and retaining a reading. The other is the possibility that the egr valve is opening too wide, causing excessive flow. Disconnecting the valve will confirm that. Let us know... Ray

Thanks for the reply! Yes we swaped 3 different throttle position sensors a while ago, sorry i didnt say that first, but we just checked the egr valve yesterday, but we are not sure if it works or not, we took it off and pushed on the inside of it the air flowed through it, but i dont know if it is stuck open. so if i take it off and run the car, that would solve the problem, i just need to change the egr valve? other note: my lifter or rocker arms are knocking (yea, this car is in bad shape) would worn out rocker arms be causing this?

thanks a lot!

-nick