I have a 2007 F150 with 90,000 miles. I have been having some miss firing off and on for a couple of months.Figured I better have it looked at. I took it to the first garage ( non dealership ) to have it looked at.They ran a diagnostic check on it and found it indicated there was a problem with #4 cylinder.

They changed the plugs twice in the event one may have been defective, put a new coil on and still a problem. Then they replaced the fuel filter.Still no better.They finally called and said they didnt know what the problem was to come pick it up.

They recommended I go to another garage better equipped and staffed. I went there and they did the same but changed the injector also. Still didnt resolve the problem.They then said they didnt know what the problem is.I brought the truck home and now it sits.

I was planning on trading it but with the way it is running I most likely won't get a good trade value for it with it running as it does.


Any suggestions as to what the problem is and how to fix it.

Thanks , Bob J.

First....they did change the rear one on the passenger side, right? Compression tests would be the next step.

Yes they did.#4 cylinder.Plug,coil and injector all changed out new.Plus a new fuel filter.

Are there any codes indicating a rich/lean situation?

I had a miss develop and my injector hit the fan.

Ryan

How is the weatherstrip above the pass side? Also check the heater hoses above the #4 coil. I've had several of the hose clamps leaking there, dripping antifreeze down onto the coil, shorting it out.