[XoXSciFiGuy]

I can't answer all your questions, but if it isn't tossing a Check Engine light on you...this is a good thing.

Could be it just needs a good full tune up with decent quality parts. I would start there just on general principles. New cap and rotor, good NGK or Denso spark plugs, new (and high quality) spark plug wires, new air filter. Have to eliminate the obvious first. And I would change out the fuel filter just for the heck of it because its only about six bucks.

NOTE ON FUEL FILTER: Fuel pressure is at 35-40 pounds pressure, which is more than the air on your tires. Can be dangerous.

Do the following in order, and only when engine is stone cold:

Turn ignition key to ON position first. Wait for the 'whirr' noise to stop. Turn OFF ignition. Pull fuse for fuel pump. Disconnect battery. Get container to hold gas. Disconnect hose, pinching it with vise grips before you do. Stuff hose into gas container, release vice grips. Let gas drain until it stops. Replace filter. Clean up any spilled gas.

Put fuse and battery back in truck. Restart truck. If you try the quickie route, possible fire in the engine bay can ruin your day.