Van does not start or starts and shuts off immidately, have 60 psi fuel press, have spark, gas smells terrible.has been sitting for 1 year.

Anti-theft problem ? Computer disables fuel injectors after a couple of seconds ,that's what it sounds like . Does it have a SECURITY light on ?

it sounds like it kicked the timing chain , the last time you shut it off

Check your fuel pressure it should be 50-55 psi.Sounds like the fuel pump is to weak.

you should have 60 -66 psi there is a updated fuel pump with a new connector to splice in i would buy a ac delco pump and make sure you check the fuel filter first and if it does end up being the pump its a good habit to but a new fuel filter with it.

If you have spark and fuel it should start. You must have min 57 PSI fuel pressure for this vehicle to start if it is the 4.3 Vortec engine. Also the cam sensor and the crank sensor control the spark. Does it have the check engine light on and if so what is the code or codes does it have? Need more info to help you out more.

Spray some carburetor cleaner into the engine an see if it starts ! I don't think 58 psi fuel pressure is enought ! Has to be above 60 psi .415-455 kPa (60-66 psi).

How long since a tune-up? Any applicable trouble codes? If you have that spider fuel system, that system is noted for problems. Check the fuel pressure, key on engine off, 60--66 psi. After it starts it will run with less pressure. In the past I have seen service bulletins about the poppet valves sticking, the fix was a cleaning procedure, that was a shop procedure.
Mainly the bulletin talked about hard starts in the morning because of poppet valves sticking, after it starts it will usually run fine the rest of the day, after it sits overnight, you have the same problem the next morning.
There could be other issues?
If it cranks good but won't start, have a helper crank it while you visually check for spark at the spark plugs. If spark everywhere, use a gage and check proper fuel pressure and fuel injector pulse.

Check your fuel pressure regulator. Remove the vacuum line attached to it and hook a fuel pressure gauge to the schrader valve on the fuel input line. The gauge should read at least 40 PSI, probably closer to 50-60 or more.

If it's lower than that, you're not getting enough fuel to the engine. It may also be stuck shut, meaning that you're putting in too much fuel.

If you find that the exhaust smells of fuel after cranking for awhile, there's a good chance that you're flooding out due to a faulty FPR.

Check for mouse chewed wiring...I have had them chew through plug wires when sitting for a while...good luck...Lee

replace fuel filter and check fuel pressure.