Think i'm having either a fuel pump or fuel filter problem. here and there after i get gas the truck wont start for about 3 hrs. How can i tell ?

if no fuel pressure and pump relay is working than fuel pump bad fuel pumps can be 3 hrs old and go bad

Fuel filter,air filter,could be fuel pump,

1- Tune-up (spark plugs, air filter, fuel filter, rotor, and cap.
2- Quality of the gas (low flash point)


Hope it helps.

First look at fuel pressure pump jam

Could be a small amount of rust got into fuel filter from sitting empty, try changing fuel filter before worrying about the fuel pump.Filters could be partly plugged and its always smart to start with the cheaper fixes first.

would say lack of fuel ie check fuell pump if carb is it blocked

Yes, the fuel filter is in-line, up from the gas tank, usally in a bracket mounted to the frame.

Cheapest route is your fuel filter...you might have gunked it up! Try replacing your filter first.

Did you replace fuel filter...? If the filters all clogged up it wont matter if you changed the fuel pump cause it will burn the new one out also... Plus you use Sunnoco gas dont you??? Let me know about that and tell me if you changed fuel filter if not do that real quick.

Thanks,
Steve

you need to check fuel pump pressure at the fuel rail the next time it shuts off ,
have a great day.