corvette95

Can anyone help me, I have taken it to the local shops (all of them) they keep swapping parts and not fixing it. Runs perfect, in good condition BUT if you turn key and dont hold it to start long enough(say half second) or it doesnt start and run instantly -which it does 99% of the time, the truck will NOT start, it will just sit and spin and not even hit a lick trying to start for several hours (cranks ok - just no start). Only does this when it doesnt crank on first try - hot or cold can re create problem at will. Have tried:fuel pump, coils, computer etc. Spark is there when it wont start, seems to flood out. Injector is firing too!