Intermittent no-start

Sometimes my Bravada won’t start. It cranks good (new battery) and I can hear the fuel pump , but it doesn’t fire up. I just got it back from the repair shop.???

check all wiring connections to make sure there are no loose connections. Check to see if sparkplugs are firing.

@Zoner please post back with model year and engine

By the way, what was done at the shop?

It’s a 1992 Oldsmobile Bravada, 4.3 Ltr vortec, automatic. It sat for 3 months but had previous interm. no-start, but not at shop. The shop put new battery and belt and I picked it up and got gas and drove it home. Two days later no-start again. ???

Check fuel pressure.
Check spark.