I have a '89 Formula Firebird with L03.
When I start the car, after driving it ,then letting it cool from 45 to 90 minutes the car Revs to 1500rpms, then quickly to 400rpms then back and forth for about 10 seconds, then stalls!!!!
If I try saving it by giving it gas, it does not help!
I took my car to the local (best in town) fuel injection/carb shop, and they looked at it and drove it for 4 days. Could't find anything wrong, besides the fact that when my car "reved iratically" the fuel pressure went down. But when the car is driven or it running normal it stays at about 10psi, normal!

I think the fuel pump is going bad, so I lifted up the carpet under my t-top bags and cut a hole in the floor were the fuel sending unit is. Droping the rear-end and exhaust would be exhausting!!! I think im going to order the Granatelli Motor Sports 255lph fuel pump pn GRN-GM722-2 from summit racing.

Does anyone think that will cure my problem. Any good ideas of what else it might be??? ECM, Fuel Pressure Control Moduel, PROM????? hELP!

tHANKS
Ben

 

TPS or something to that effect.
Your TPS could be going bad and/or your timing is off.
Most likely your idle is off and your timing is a little retarded and your TPS needs to be adjusted or replaced.

 

Mine was doing the same thing until it got back up to temperature again. If I gave the gas pedal slight preasure to feed it more gas it would run until the idle came back to normal. I swapped the fuel pump and it fixed it. Before you go to all the touble of replacing the pump, try the pump relay. I have heard that may cause the problem also.

Hope it helps.