5.4 issue

[no-tel-in]

Workin on my Mom's 04 expedition, started missin early this week, hooked AE to it, came up with #4 misfire, so I got the COP and replaced it, drove it, no issue. 2 days later it has developed a hesitation on take off, no codes at all. Looking at it now it appears when I had my big hands back there I cracked the MAX A/C valve because there is now a drip from it. For now I have a 5/8" barbed union in there with 2 hoseclamps.

Any ideas on the hesitation?

[powerhoghp]

I don't remember if the 5.4s suffered from this as much as the 4.0s and 3.0s, but check for moisture in the coil and that the egr valve isn't stuck. Then check the basics: filters, fluids, spark, etc.

[no-tel-in]

Ok I got her done today. Took it all back apart, replaced 2 more COPs I suspected affected by moisture. so now #2,3,4 have new COPs. Pulled one plug to inspect, and decided to change them all, they looked bad, but were original 120k plugs. Installed 8 new motorcraft plugs. Pulled both fuel rails, all 8 injectors and cleaned them. Checked egr valve, appeared good. Put it all back together and she's as good as new!