RFinelli81

Hello,

My girlfriend has a 1999 f-250 Light duty with a 5.4 in it. The service engine light came one and the trouble code was a misfire on cylinder 4. I just soent the morning changing the spark plugs. Not fun at all. I still have the troule code. I hooked a voltmeter up to the fuel injector and it is getting juice. I also switched the coil pack/boot with cylinder #1 just to make sure that wasnt it. #1 is still working fine. The truck idles and drives rough, if you didnt already know.

Any suggestions??? before I take it to get looked at?

Phyer Phyter

Did you clear the code and it came back?

FX4-71

Maybe check those coils you replaced. When I had my 98 5.4 I replaced damn near all of them as they randomly went bad and twice I bought bad coils over the counter.

llhrpm

take all the injectors out of the left side #1 #2 #3 #4 look in the top and see if you find any fine rust laying in there that injector on the top is about a 1/4 in deep i would take starting fluid and spray them and then a air compressor and blow thru them they all can work fine but some maybe plugged up