2001 gmc safari, cranks but no start. Fuel pressure good, has spark, no codes, no engine light. Vehicle was running fine then shutdown. Will not run on starting fluid. Tried PCM from sister vehicle, still will not start even with security code programmed. Has TPS signal. Battery voltage good. All fuses ok. Fuel pump relay ok. Has voltage to crank sensor. Need help!!!!!!!!!!!!!!!!!!!!!!

fuses good< oops
scan the PCM see errors cranking OMG it tells you why:? sure can.
forgot the 6 new spark wire plug set, replaced 1 by one never all at once, 6 new OEM type spark plugs and gaped correctly
22 year old spark parts are no good ever.
test for spark on all 6 yet, spark is 1st or there can be no FIRE.

4.3L cranks but will not start and run and stay running.(problem1)
fire cant be seen, but spark can.
1,2,3 engine,spark, fuel good 1,2,3 in that order
spark and fuel can not run a dead engine, so 1 is first engine'
compression good 150psi up not lower, all near same
next is spark if EFI sees spark
actual fuel pressure not told just OKay. pressures matter big time in EFI, and at cranking for sure. then idle and WOT later.
engine is free running so all tests are safe, cranking too.
the service manual covers all fuel checks cranked, balance test and leak down tests.

watch scotty
https://youtu.be/064Ilsz8Fzg

Do you have any codes or an engine light on, in your dash board ? Have you checked for spark at your plugs ? There are many things that could cause a vehicle to not start. Bad camshaft/crankshaft sensors. Poor ground wiring. Defective spark plugs or wires/coils.

Could be a long list of things including low fuel pressure.
Someone would need to figure out if it is an ignition problem such as the plugs or the cap and rotor, or a fuel problem such as low pressure from the pump, a dirty fuel filter, or a vac leak.
If the check engine light is on you should start with the trouble codes in the computer.

It almost sound like a bad coolant temperature sensor, but that is just a shot in the dark. I did have a 1995 LeBaron that had the same problem, and it had a bad coolant sensor. Is the check engine light on? Are you getting spark when it cranks but won't run? The fuel pressure itself, may have something to do with it, and with fuel pumps, they have a PSI specification, but there is also a volume of fuel amount, such as 1 pint in 15 seconds, I'm not sure what that amount is for you vehicle, but that maybe something to consider. I'd check for any vacuum leaks too.

Usually if no rpm signal, the vehicle won't start. Engine cranking, did you check for spark at the spark plugs? The fuel pressure you listed may have been the initial prime. It sounds like no injector pulse. The rpm signal comes from crank sensor. If your missing rpm signal, may thought is the crank sensor.
Were there any applicable trouble codes?

Do you have the 4.3L engine with spider fuel system? That system is noted for problems. Key on engine off, fuel pressure, 60--66 psi, use a fuel pressure gage. It needs that pressure to start, after it starts, it will run with less pressure.
There could be other issues? Engine cranking, you have spark at the plugs and fuel injector pulse?

Could be fuel pump, is the pump running when you turn key on, you should be able to hear it. You are likely going to have to take it to someone with a pressure gauge to make sure it is getting proper fuel pressure. Fuel pumps commonly go on these vehicles

Try changing the fuel filter and checking the fuel pressure at the shredder valve. The readings should be 60 to 65psi with the fuel line pressurized with the engine not running, once the engine is running. It should drop by 5psi. Start with the simple things first. Keep me posted, be glad to help.

POSS FUEL PRESSURE LEAKING INTO INTAKE VIA FUEL PRESSURE REGULATOR

My 1997 safari was doing the same. After being shut off for a short period of time it started as if it was flooded. If I put the accelerator to the floor it would fire up. As well, I had no engine codes to report. I replaced the fuel pressure regulator and everything is great. It was leaking fuel into the engine causing it to act flooded when starting. Once started, the computer system made adjustments for the leaking fuel so the engine ran fine. If you turn the van off and immediately try to start it, it should fire up. (don't give it time to leak extra fuel into the engine)