the car started fine after sitting for 9 months with full tank of gas. it started fine. i let it idle until it got up to normal operating temperature. then it just died.tried starting it. it would start and then just died. squirting carb cleaner in the tbi the engine runs fine. i thought that it was bad gas so i drained the gas tank and replaced the fuel filter. i put 3 gallons of premium gas in the tanks and it does the same thing. if i start the car and pump the gas pedal rapidly it will continue to run roughly and back fire thru the tbi. i'm thinking varnish build up in the tbi, i'm new to this so i don't have a clue as to what steps to take next. if i turn the key on i can hear the fuel pump run for a few seconds then stop. any and all help is welcome thanks greg

well,are ya sure the fuel pump is still operating at the correct psi?
Have ya connected a fuel pressure gauge to it?
If thats all good,I would check into the filter.
I had a v6 3.1 mpfi car a while back that started right up and ran great until you tried to give a lil throttle,then it would choke and rumble and then stall.
Turns out the fuel pump was only putting about 13 psi instead of 40-45.
Changed that and car was as good as new.

If I recall correctly, you'd only want 9-15 psi or so with a Tbi. They don't require the 40-45 psi that MPI setups do.

His car was MPI,
I would also agree, check your fuel pressure.

im having the same problem with a 91 camaro rs 305 tbi damn thing starts then back fires and if it does run it idels way off. Very rarely it will idel smooth. i only put 93 octane in it so it cant be the gas

Check timing,dist. pick up coil and if you timing chain is really worn it can cause this sometimes.

timing chain looks fine and the timing is about as good as it gets