Q&A

 Enthusiast

Replace the fuel pump.

 Master

It could be many things, unfortunately and without experiencing the problem first hand or being able to do some basic diagnostic tests its hard to say. Start with and don't overlook the basics. If service has been neglected start there. Check compression is even when replacing the spark plugs, check engine intake manifold vacuum is about 21 in HG at idle or it would indicate a problem (perhaps engine mechanical). Verify fuel pressure and delivery is correct, 28 to 45 psi at idle engine running. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online
Replace the fuel filter under the left rear of the truck.