No start 1999 Pontiac Sunfire 2.2

I also pulled throttle body off and cleaned cked Iac cked throttle positioning sensor and cked all vucumm hoses

When you used the fuel gage, after you built pressure, did you turn the key off and see if pressure will hold for a bit? If it drops like a rock, check for fuel pressure leak. When you put pedal to floor, it may go into clear flood mode. Is it trying to flood? Did you check sparks plugs after cranking, are they wet, bone dry? You do have spark at all spark plugs?

Yes when I cked fuel pressure it dropped slowly . I cked spark at all plugs after trying to start so many times they were fouled when I put new plugs in I tried to start it pulled plugs back out they were dry

I also pulled all injectors out to see if fuel was spraying into cyl. They were .What was weird is the car started with the injectors out ran for about 3 seconds and shut off I have pulled intake off cked for anything plugged nothing found .I was thinking maybe convertor problem removed O2 sensor in front of converter still no start

This might sound weird but would shift sensor do this.? Maybe a safety switch malfunction..seen a dodge truck do this once..and it would start in neutral but not in park ..just a thought

i tried that the weird thing is I have great spark at all cylinders,correct fuel pressure I know the injectors are working I removed fuel rail and watched them spray out, the timing is right . Correct compression at all 4 cylinders. I've worked on cars for 25 years and I cannot find nothing wrong that would make this car not start

Another scenario ..possible the engine got vapor locked ? Would explain fuel pressure and injectors working fine ..also why the car temporarily starts after pulling the injectors..but why it would do that outta no where is a mystery