Sometimes no start and stalling

Van with 120,000K out of the blue would not start. Changed the plugs as they were used up. Started fine for 3 days. The next day and it would not start, left until hours later it finally started. Got it home shut it off and tried to start it ran for second(rumbly) stalled could not start.
Checked for spark there was lots, still wouldn't start. All of a sudden it started and ran fine. I thought maybe the fuel filter but under hard acceleration still runs fine. Maybe the fuel pump? Do they act like that?

Sounds like an electrical problem waiting to come back. Take it to a garage to have your trouble codes read. Your computer probably stored some faults.

The service engine light isn't on or does that matter?