My 91 camaro rs 5.0 is driving me crazy. I got the car in a trade it has 130K.
I have put a new fuel pump, filter, distributor, cap, wires, plugs, belt, exhaust, o2 sensor, ega, TBI rebuilt and temp sensor. I have seafoamed it helped a little. The cat and Map sensor seem good. I am not getting any codes.
The car will start and run fine for 1-2 min then it will start surging, when I push the gas and hold it at like 3000rpms the engine still surges up and down about 500 rpms. If I try to drive the car back and forth in the driveway it dies but starts right back up. Run the car for 10-15min it starts to smooth out and drives fine. Shut the car off and let it sit for 30min and the surging cames back.
I have dumped so much money in this car and I still cannt drive it.

 

my 91 5.0 is having same issue replaced everything you mention expect temp sensor and fuel filter. ugh!

 

good luck, I have never hated a car as much as my 91 camaro no matter what I do nothing changes the surging. Its parked for the winter I may junk it in the spring.

 

lol took mine to a mechanic today. got 2 things fixed that was wrong. 1 being when last owner replaced fuel pump look like they used a aftermarket connector to the relay and 1 of the wires was melted. now fixed. 2nd my coolant temp sensor connector was hanging by the starter not hooked up/ grounded. so now my car idles as it should. but my rpm gauge still fluctuating and stalling issue. may have fouled my plugs and still need to get my fuel pressure tested i believe.