In your other post I think you said you could hear the pump doing its priming cycle. In that case, you've got power
to the pump, so you can probably skip the relay, and there's not a heck of a lot that can go wrong in a fuel filter. A
cheap pump can go bad without warning. If you're on good terms with the previous owner, perhaps you could ask
him what brand of fuel pump was installed?
What did your mechanic say the fuel pressure was?
I don't remember if that model still had the throttle body injection that my 92 Blazer had. Possibly the fuel pressure
regulator, but I'll have to do some digging to see if that's applicable to that model.
Was any work done on the ignition system, like new plugs/coil/wires? Did the mechanic check for decent spark?
Cheers-
Chris