little bit of a miss

[jamesbalderastx]

Have a 03 4.0 with 42,xxx miles on it. Replaced plugs and wires with oe wires and Bosch +4 plugs. Had a rough idle still (common with coil pack I've learned) so I got live wires and the screamin demon pack. Just put it in and it still idles rough. Not near as rough though. Maybeim being too picky? Vehicle before this was an 01 ram 2500 with a 24v cummins and being a diesel it never missed. And now I have this truck and the miss drives ne up the wall. It's only at idle. Power band is impressive for a 6 cylinder especially after the new wires and coil. Is assume its been sitting awhile because of the low miles and yes I've changed fuel filter, air filter, did the sea foam both through the intake and through the fuel.

Maybe change injectors? Cause my fuel economy isn't so great either. Maybe 15-16 mpg

 

[Maritime Storm]

Swap out the Bosch plugs and properly dispose of them in the garbage where they belong. Then drop down to your local Ford store and pick up a set of Motorcraft plugs before you do any further harm to that engine. Autolites are a suitble substitute if Motorcraft is not available.