Hey all, First off its an '06 5.4L with an intercooled Eaton blower making 7.5lbs. I have what i think is a misfire at idle, more noticeable when the engine is cold. It almost feels like someone thumps the truck every second or two. The truck will also hesitate and almost bog down at around half throttle, doesn't do this all the time though but quite a bit. I just changed the plugs which had about 25,000 on them and it seemed to help a little but not much. It doesn't throw any codes. Think it could be a weak coil? I have the torque app so i can monitor timing and what not if that would tell me anything. What do you guys think, any ideas? Thanks

 

I have no idea bout blowers or what else you have done to your engine to handle the blower, but what you are describing sounds close to what I went through a few months ago and it was indeed a bad coil or 2, so I changed them all and that cured my problem. Mine wasnt' throwing any codes either till it got real bad, then the codes started.

 

I actually just ordered a set of Granatelli 60,000 volt coils from Troyer. Hope that's it! Once this is sorted out ill be getting a custom tune either from Troyer or JDM. Anyone have any experience with either? I know Troyers wait times can be ridiculous. Thanks again.

 

How did you narrow it to the coils? By the codes? What codes were you throwing? Thanks.

 

The first time I had a bad coil it was starting to miss in overdrive at the slightest road incline, I let it go until it started to do the same in 3rd gear, that is when it started throwing codes. To be honest, I dont' remember offhand what the codes were(I have had quite a few codes in the past few months), sorry. They found which coil it was, replaced it. I then went another 100 miles or so and it started doing the exact same thing, so this time I went and changed them all and that seemed to fix the issue and I havent' had that issue since.