January 27, 2011
my 2000 f150 5.4l has had a curious issue happening lately. Engine will run on (I`m guessing here) sometimes 7 or 6 cylinders. The when I last checked the error codes it was for rough idle (I forget the codes, but I have them somewhere). Sometimes it will start up and run real rough then smooth out to all 8 cylinders. Then it can switch back and forth between dropping cylinders and smoothing out.I was driving it the other night, ran for about an hour straight no problems. Started back up after an hour or so, drove 5 minutes, got on the gas leaving an intersection and then 2 cylinders stopped firing. Kept driving, got let the truck coast on a down-hill and when I got on the gas again at the bottom, all 8 were firing again.
So, what could it be? Fuel? Electrical? I`m leaning towards electrical. Maybe corroded electrical connections on the fuel injectors?
Engine makes no knocking sound or anything out of the ordinary. Just a few cylinders deciding not to fire.
