Cold start trouble

Have a 2001 GMC Sonamoa. 4.3, 273,000 miles. Great truck, runs great. Kept up all maint. Recently have difficulty starting after sitting for a few hours. Tuned up this week, no help. Thinking maybe the fuel filter. Any sugesstions?

Good thought on changing the fuel filter, and, then, check the fuel pressure.
Two possibilities (at least): the engine, at start is rich; the engine, at start is lean.
For rich (flooded condition), hold the gas pedal to the floor as you crank the engine, for up to 15 seconds at a time. As/if the engine starts, ease up on the gas.
For lean condition, at start, turn the ignition to RUN for 4 seconds, OFF, RUN for 4 seconds, OFF, RUN for 4 seconds. Attempt to start. Results?

Thanks for the suggesations. I’ll give it a try and let you know.

Sorry about my typing.

Tried to start for both lean and rich. No luck. I’ll try changing the fuel filter next. (Maybe tomorrow) If nothing then, I guess she goes to the shop. Thanks for the info.