UA Limos

Vehicle- 2002 Workhorse P30 FT1461 bread/box truck 5.7L 130k previous running condition Condition- Cranks strong, Spark, No start Problem- Moved vehicle one day and came back a week later and had a no start. It was moved on a sunny 80deg day so it wasn't in a flood or some other crazy situation. Scanner shows no codes, cranks strong scanner shows about 175 rpms next checked spark- good spark plugs DRY. Checked fuel pump, pulled and cleaned screens although they were not bad. Pressure at check valve on top of intake is 62ish psi with key on and then 58-60 psi cranking. All fuses checked good. Pour gas or starting fluid into throttle body and it runs properly until it is burned off. Will not stay running once burned off. I then switch spider injector assembly (regulator is part of it as well) with a known working one with no change. No idea on how to proceed or if I am missing something easy, trying to find which wires are the signal wires for injectors to verify if they are getting a signal or not and that would lead me to believe it is a ecm/ecu problem.