rocketman17j

Ok i got this vette from a guy that said it wont start and heres the story. It was running fine and he brought it back from getting a new a/c compressor on it and charging the system. When he got hom it started running like crap.Over the next tew tims out it ram worse and worse and finaly wouldnt start.
Now I have done the following.
new injectore-they are firing electricly
new cap and rotor
new filter and fuel regulator
new egr
new fuel pump.
ck compression between 135-155 on all cyl
have spark
Now i tryed either and nothing when it does TRY to start it sputters for 1-2 seconds and than wont try any more. after the pump last week end it kinda fired for 5 sec and than no.
So WTF is wrong with is POS? is it a VAT thing,? i timed it. Can it be a bad coil that wont fire under compression? I even herd about a wire that the computer advances the timimng so could be a bad comp
IM AT THE END OF MY ROPE- FUEL<COMPRESSION AND FIRE---should run

All advice would be aprecieated

Rocky