Kmelino

91 f150 Custom, fairly certain it was a former city truck from up north.

Its passed through several owners, and I didn't ask many questions when buying it, it was dirt cheap.

That being said its got this bucking that happens when I push on the accelerator hard, seems to happen more often when its lower on gas. It also nearly dies then revs on cold start in idle. The check engine light isn't on currently, although it randomly flashed the check engine light two times nearly a year ago

The transmission fluid still looks good, and I drained it and refilled it a year ago on friend advice. It lacks other basic transmission symptoms so I may be missing a really obvious need for a trany rebuild.

I've replaced the fuel filter, and dropped the tank and cleaned it out (although this appears to have been unnecessary as it was super clean). Replaced the spark plugs and wires.

Has anyone else had this specific problem? Ideas?

88xlt

I would put a container of fuel injector cleaner in the gas tank. Just follow the directions on the container.

BLDTruth

I would measure fuel pressure. Does it have two tanks? If so do the symptoms persist on both?

stxlt

Have a look at the Throttle Position Sensor if the other ideas mentioned do not solve the bucking. The sensor is mounted under the intake hoses on the throttle body. The part is $60 locally but dirt cheap at Rock Auto.