jaybird531

I have a 2000 f150 with a 4.2. I have a cylinder 4 misfire code...I replaced the plugs, wire and coil pack. I erased the code, drove it for several miles and the check engine light came back on. I checked the code, and again the cylinder 4 misfire code was back...It is the only code. Is there a known issue, or has anyone gone through this, and what was the cure?

westtnfx4

Have you checked the injector?

C Denny Run*

Never owned a 4.2L, but if that cylinder is getting spark then I would imagine the misfire has something to do with fuel delivery. Pull the plug wire for cylinder #4 off the coil pack, and see if makes a difference, if it does, then it's electrical. If there is no effect, then it could be an injection problem, I would assume.

C Denny Run*

I had a similar problem with my 03 Ranger 3.go, the problem turned out to be the cam synchronizer. If it turns out to be an electrical problem, that would be my next thought.

westtnfx4

Next in line would be the CPS (cam position sensor)