oI have a 1990il sen fuel filter, mass air flow sensor, throttle position sensor,

battery has a full charge and all that good stuff? did you use a gage and check proper fuel pressure? 60--66 psi, key on engine off. are you saying, once you prime it, it will run fine? In the past, I have seen service bulletin about fuel poppets sticking, but, if you replaced them? Another thought, there might be a voltage drop on circuit/s having to do with fuel system, fuel pump--fuel injectors, whatever. Engine cranking all your systems get battery voltage. Engine running, the systems get generator voltage. The generator voltage can be several volts higher than battery voltage.