ok i just picked up a 1991 gta.
the car sat for about a year with gas in it.
i had to replace the intake gasket cause of a leak and the starter because of a dead spot.

i did a tune up to it while i had the starter down.
new plugs, wires, cap, rotor.

the car was running rough before i did it. the old plugs were black.
it has no ***** what so ever.

ok i started it up today and it fired up fine but still has that almost a miss.
when im driving it i can hold the throttle at one spot and the car will "buck" at speed. i can take and stop and put it in park and it does the same thing.

i put fresh gas in and cleaned the injectors when i had the tpi apart. they were spotless to begin with.

the problem got alot worse when the tank got to about 1/4 full.

i could put the pedal to the floor and it will not move just falls on its face but does not stall out. happens after i made a right hand turn.
i went to the gas station and filled up to 3/4 tank and it stopped doing it but still runs like crap.
i can also hear the pump surging with the engine when im in the car.

possible that the pump is on its way out?

i havent checked fuel psi.

it doesnt smoke black or anything out of the pipes and it starts right up.

i heard 91 camaros had a tank problem would it be the same for the trans ams?

Edit.... i did check all the grounds under the hood and they were all good with no corrosion.

the pump surges from loud to quiet and loud again. i can hear it inside the car with the windows up.

edit 2..... i forgot to add its has 137k on the clock. auto. stock exhaust, crappy dual cat setup, red lol

 

eh being that my brain has been fried in the florida heat working on this thing i forgot to ad one more thing.

when its in park hot or cold it revs extremely slow. like super slow.
i have to put the pedal down half way to reach even 4k.

dont know if that helps any but figured id let you guys know.

my buddy was thinking cogged cats.

i could cut them out and straight pipe them. no emissions testing here.