Coil question

[gambling209]

I have an 04 with the v6. I have a problem with it running rough when it’s cold. Its fine after it warms up or when not cold out. Diagnostic said coil number one and two are bad. Replaced them again with motorcraft stuff and new spark plugs. After a week it’s back to doing it again. It said coil number one is bad. Actually says misfire on cylinder one. What could be the problem if it’s constantly saying new coil is bad?

 

[AmsterDutch]

Are you gapping the plugs correctly with proper specifications? Are you using dielectric grease on the boots? What is your fuel pressure at? What scanner are you using?

 

[04_Sport_LS]

Check your wiring harness. Especially the clips that go on the coils. The lock tabs get brittle with heat and age, and can pop off causing a loose connection.

If the clips are broken, use a zip tie to keep the connector on tight. The auto parts stores sell a couple different replacement connectors, if you wanna go that route, (if this is the actual issue.

The other possibility is that there is an issue with the PCM. Or a defective O2 sensor causing a lean misfire on cyls 1 and 2.

 

[joegr]

It could also be a marginal or dirty fuel injector(s).

 

[gambling209]

I’m going to look at the connection and figured this would be the number one thing. It does perfect when it warm out side or motor has ran enough to heat up. Have a part number for the new clips?

 

[04_Sport_LS]

Not off the top of my head. Your local parts store should know what to look for.

Joe may be correct about the fuel injectors. I was thinking the same thing... but wanted you to verify a possible electrical issue first.

That's why I recommended trying the zip ties first. Try them on both coils... and both fuel injectors too... if the factory clips are broken.