my 93 z28 is almost a new car under the hood but now it won't start! i have 147,700 miles on it. i've changed the battery, ignition coil, fuses, egr valve, spark plugs, wires, trans was rebuilt with slight mods, added a cold air intake, changed the ecm, fuel filter and starter. all this was done within the last year. when it does start, sometimes it will cut off in a few seconds. if that doesn't happen, it's real slow from take off. it feels like it wants to choke out from too much gas or not enough (because i'll be giving it gas when i notice this). after i let off the gas, then it clears up in about 30 seconds. i hit the gas again and the car runs fine. sometimes at a light it will feel like it wants to stall or the rpms will increase on its own. in idle the rpms increase on their own sometimes as well while parked. once the car is turned off, i can get about three consecutive starts in 5 minutes. once the car sits, it won't start at all unless, i release gas from the relief valve under the hood, or loosen the gas cap (sometimes). under the hood, a jet of gas will shoot out most times. a few times, i haven't gotten much gas out the valve. i was about to replace the filter again, but when i loosened the hose leading to the engine, gas began dripping out constantly. the only things that haven't been changed are the distributor, the cap and rotor and the fuel pump. i need help bad! if anybody is in the dallas metroplax area, please contact me at blacksmith73_99@yahoo.com. thanks.

 

i would change the cap and rotor, carbon tracking in the cap can give odd problems

 

Have you tested your fuel pressure??