My 4.0 misses when starting to pull out and while at cruising speed. Changed plugs, wires, and coil pack. Ran injector cleaner through it also. Pulled a code for #1 cylinder miss fire (key on egine off). The missing tends to come and go. Sometimes it will be fine while and then start missing again.

I am open to all suggestions.

 

Did the miss occur AFTER you replaced the plugs, wires & coilpack, or was it doing this missing beforehand????

If it began after the replacement work, I'd suspect a faulty plug wire or maybe a cracked plug insulator or faulty spark plug, or even a faulty coilpack coil.

If it was doing it beforehand, then maybe we have to suspect the coil pack electrical connector wire or pin for the #1 coil, or the #1 fuel injector.

Does the problem seem to be worse when damp condiions are present????

Does it seem to be present only when the engine is under load????