I have a 99 F-150, 4.6L V8 with 216,000 miles on it. The truck reads no codes when hooked up to the computer and no check engine light is on. Several mechanics have ran diagnostics on my truck and can not find a single thing wrong with it. Driving it with the computer hooked up also found no problems, no misfires, MAF good, etc. I just replaced the fuel filter and have recently replaced the upper plentum gasket, spark plugs, plug wires, DPFE sensor, PCV valve, and my fuel pressure is at the top of the desired range. The truck runs excellent some times but then I can shut it off, start it back up, then drive away and its running sluggishly. When I reach hills, it slows down. If it is windy, that also slows me down drastically. If I am on the highway going 70, I can press the pedal down pretty far and get a very delayed response. The truck will slowly pick up speed after a few seconds and when I accelerate fast, I can let off the gas slowly and it will continue to rev the engine. Any clue as to why the truck has so little power when all engine tests come back good? My truck has 4 catalytic convertors but they can't all be plugged can they? Any help is appreciated.
have the same problem?
Tuesday, May 19th, 2009 AT 1:01 PM