Hi guys, really at a loss here.. long story short 1998 LS1 TransAm.. the car now has a 6.0 in it for going on 2 years now.. now.. swapped by me, the engine is practically brand new and this car has ALOT of new parts on it.. and I know my way around this car, had it for 9 years now so I'm not exactly a rookie.. anyway, car has had a parasitic battery drain for a couple years now(had the problem before I even put in the 6.0 engine) I even went as far to install a racetronix cutoff switch to disconnect the battery overnight to stop the battery drain, it worked, had it that way for a year or two.. WELL, the other day i drove the car and it ran great but when i went to start it at the store it would crank and crank but never start up! Listened and couldnt hear the fuel pump priming, something i am very familiar with.. I changed the fuel pump, still the same problem..it doesn't appear to be a fuel pump relay or ignition relay as I have changed them out with others i had laying around.. the fuel pump clicks on for about half a second as you turn the key on, kindof a whhrrr noise, i mean just for a split second, and then cuts out, and i mean not even long enough to build pressure, a split second literally..car is getting spark and cranking but not fuel..10 psi on the fuel line.. brand new fuel pump so its not the fuel pump, if i unplug the fuel pump connector and put 12v to the fuel pump on the black and grey wires I get the fuel pump to run and it build pressure as normal but for some reason the car still didn't start.. it's almost as if the fuel injectors aren't getting a signal(i have not checked that yet) I do know my fuel pump relay should be good and looks like is getting power it's like something is cutting off the fuel pump. And I am fully aware of the VATS system as it has been bypassed with a custom order resistor module and my security light isn't on, plus the car still cranks so the VATS system shouldn't be an issue, i had a guy tell me from LSswapbox.com that it's a vats issue, but I do not see how as when the VATS system is engaged it does not allow the car to crank, guy keeps telling us that over and over, I've been fully aware of how the VATS system works since I was 19, 20 years old..anyway, I'm leaning towards a bad ECM computer as I do not see any bad wiring or grounds, all that has been gone through shen i swapped the engine as a precautionary double check..i even replaced the main ground wire from the battery to the side of the engine block.. I even replaced the ignition switch on the steering column(the plastic piece with the brass contacts) I swapped and switched relays hoping it might be a relay causing the parasitic drain.. so im think a bad ECM might have caused that all along AND now it's gotten worse and the circuitboard has a bad spot and isnt allowing my fuel system to turn on.. it's a 98 so it has to be that year and that year only on the ecm unless you repin your harness and get a 99+ ecm.. so, I'm not real sure what to do next, car has brand new engine, new ps pump, alternator, brand new air conditioner parts, new motor mounts..has umi subframe connectors, umi trailing arms.. it even has a 6.2L starter off of a low mileage 2020 camaro which i wanted because it has a heat shield on it and i thought that'd be better.. car done pretty good until whatever this electrical gremlin is reared its head, car is now setting and won't start.. but i can't really afford to pay 7 or 8 hundred plus dollars to have this ECM reconditioned and have the car still not start, anybody have any ideas? What else could it be? Or am I wrong to think it's the ecm?

So, in summary.. car has had a parasitic drain for 2 yrs now, but always started and ran fine if you disconnected the battery overnight or used the quick battery disconnect switch.. well now the carxwon't start and build fuel pressure, fuel pump is brand new, getting switched power, but does not run long enough to prime for the normal few seconds it is supposed to.. vats is bypassed with a resistor, car is still cranking just NOT getting fuel! No bad wiring or relays that I'm aware of.. wires look pretty damn good, mechanically car is pretty clean, no corroded wires, but the paint is faded and original electronics that are 27 years old from the Clinton administration era.. so you guys tell me? What else??