starting issues. on 1998 Chevrolet Astro

I have a relay hard time with this one.
The van won’t start and stay running. I can start it and make it run for 2 to 5 seconds at a time by first pumping accelerator pedal a few times. With out the pumping it will not start at all.
Replaced the fuel pump last year.
The van has 270,000 miles on it.
I had it parked since last November, drove it one time in January with no problems. I can’t keep it run to do any checks at all.
Could have something freeze and break over the winter?

Sorry to see nobody was able to help with this problem. I was wondering if you ever figured out what was causing the starting problems?