My 1988 F-150 4.9L, 6 cyl. starts and runs great BUT after being run for a while gas pedal flattens out and she'll sput and stall, pull over and come to a hault and she'll start right up and go. She'll run until it happens again which could be 1 mile, 5 mile or 20 miles just never know. Thought maybe water in the tanks and replaced fuel filter after the rail fuel pump. i'm thinking it's the rail fuel pump because she restarts fine and idles fine just when cruiseing down the road does this happen. Thanks for any input..

 

You may want to have your pickup coil and distributor checked. I had an 87 with the straight 6 and had a similar problem and it fixed mine.

 

Hello i have a 1997 F150 4.6 engine. when im on the freeway and i start going up hill, my truck seems to have its power cut rapidly like its misfiring. What could it be? Has new spark plug wires.

 

Same truck and same problem here. Do you also have a whining noise coming from your fuel system. Not the usual Ford whine from the power steering.

 

Check the fuel pressure before throwing parts at it.

 

I agree, but I can't seem to find a good affordable one. Returned 4 to Harbor Freight; seems they are good for one use only, but they are only $15 there. Truck idles and runs fine at first, but stalls going uphill. Could that be fuel pressure?

 

OIL PRESSURE! OIL PRESSURE! OIL PRESSURE! look at teh gueage next time it starts, you may find the problem, mine did that found a hole in the pan. No surprise there. Anyway, is it just up the hills? o rwhen you out it in neutral, and put it back in drive too? Mine does the samething every now and again. Transmission could have a sensor problem like what mine does. or your fuel pump could have a serious problem. but considering its an 88', not so sure.