1997 Ford F-150 truck mileage: 79,000. The problem I'm having is with the fuel system. This is a problem that started all of a sudden. The truck runs fine first thing in the morning but when it heats up it, starts to run suggest like it's not getting enough gas. At a high speed (60 mph) it has a bad vibration. We changed out the spark plugs and fuel filter, which was pretty well clogged up. It ran fine for a while but seems to be a reoccurring problem. I feel that I may have got some bad gas when my problems first started. Any advise?
Check the fuel filter again. If plugged, you will want to flush out the fuel tanks and also check and clean the fuel pump pick-up screens. Worse case scenario is you may have to replace both fuel pumps (they have to be replaced in pairs).