All sorts of trouble with my 94 gt

Okay first off, i apologize because this will be kind of lengthy but please stick with me I'm at my wits end with this friggin car already.
So here's the problem. The car will crank fine and will run for MAYBE 2 seconds then die. I have replaced: injectors, fuel pump, timing chain, distributor, alternator(not related to problem at the time). I have no more clues as to what it could be. Does anybody know what the hell is going on? Could it be the ECM or any other computer related problems?
If it is computer related, should i just say screw it and do the carb swap? will that solve anything? or should i somehow get a new computer?
Sorry about rambling but this car is driving me insane

OHHH and one thing i forgot. Ive plugged in my tuner for my ranger to use the diagnostics mode, but it doesnt even turn on. It's like it doesn't put out power. I've also tried two others types of scanners.....same thing

I'm sort of embarrassed. i din't know the one under the dash wasn't for my car.....Ford has suprised me yet again . And that's because i saw the other plug under the hood while i was toying around with my MAF and searched for 30 minutes for the "male" end to it before saying to hell with this car and going home. I'll go and run the codes and let y'all know if you'd like