Ford F-150, 1994:
intermittent problem. going down highway, foot on the gas.
at times, will press accelerator to go faster but nothing happens, like clog somewhere.
sometimes, with foot still on gas, i will hear a popping sound coming from under the truck, (under the engine?, or drivers seat).
Usually 4-5 pops, sometimes none. But after each pop, car accelerates slightly, as if it is a slight clearing, until finally, as if some clog was opened up, the car plunges forward, so i then take my foot off the gas.
sounds like either problem with fuel getting to the engine or a problem with the exhaust.