i have a 1999 Chevrolet Cavalier 2.2L SFI OHV 4cyl. it will start but wont stay running. i have checked for codes and there is none. you can hear the fuel pump and change the fuel filter. i have psi at the injectors. i also pulled them and checked them. all 4 are firing. i have checked number 1 for spark and it has spark. only way to get the car to run is to pump the gas pedal. but still runs bad. i can get it to rev to about 3k and hold for a few sec's then it wants to die.

 

Check your fuel pressure. Sounds like it may be low. Just having fuel is not enough, it has to be at the correct pressure.

 

i checked fuel psi and its 45 psi
i have spark on all plugs


right now i am leaning to thief mode problem

 

This sounds like a sensor issue causing your problem.

When was your last tune up?