mikecoachusa

2001 F 150 5.4L WITH 230,000 MILES. Engine starts and runs great but at idle I detect a slight stumble or rough idle . vacum is good, sprk plugs replaced, throttle body clean, IAC replaced, EGR replaced, new intake manifold, tested and cleaned injectors, new fuel filter. could this be the VCT? rough idle is not violent at all.

gopherman

If you have access to a scan tool that can see enhanced PIDs, look at VCT ADV ERR PID....if you see consistent values at idle far and away from zero, it's your solenoids.

powerstrokeaaron

The 5.4 F150 didn't have vct until 04 if I am not mistaken. No codes? Need access to a scanner with misfire monitor or preferably a Ford IDS scanner with power balance to see if a certain cylinder is dropping out assuming it is engine related and not something like a motor mount that makes it feel like a rough idle. The coil packs fail all the time and cause a misfire but most noticeable under light throttle.

Odyssey11

Power stroke Aaron is correct the vct solenoid started with the 04 engines. I have a bad misfire from coil overs and they were not very old. Actually ended up being the spring inside one of them. Sometimes the smallest things can cause it...

moneyruner@aol.com

hope you changed the boots on your coils they break down because of heat and being old pull the coils if you see a white spot that is where the fire is jumping to the head replace all