2013 F350 superduty 6.2 uatomatic transmission. I have a misfire code on cyl 8 that happens only when the engine is first started cold. i can clear the code and will be fine the rest of the day or until the engine gets cold from sitting. i have replaced all the plugs and wires and the coil on 8 also. could there be a problem with the emissions?

 

injector, injector wires to computer.
coil wires to computer.

or the above connectors going bad... OR LOOSE....

 

Thanks Chuck. I checked all of the connections and appear to be ok. let me be a little clearer in my description. it only throws a code on cyl 8 and only if the engine is below lets say 140 degrees and i can't detect any misfire from the way it runs even cold. after it warms a few minutes it won't throw a code again until the engine cools below 140 degrees. is there a device that allows air into the manifold for emissions that could be lets say causing a vacuum leak until the computer shuts it off?

 

emissions ...not just for 1 cylinder....

being a cold issue... spray contact cleaner into male and female connectors (apart) for injector and coil of #8... cold also could be a Bad Coil.. but fails at cold...(not common)

also possible.. a gasket issue for #8 intake.. try tightening all intake bolts. then spray starter fluid in gasket area with engine running... will change idle speed.

 

already replaced all of the plugs and wires. also replaced coil on 8. only does it at first start or if the engine gets cold.

 

I know this is an old thread, but was wondering if you ever figured this issue out? If so what was it?

I have developed the same issue on cyl 5. Mine isn’t on every cold start, which has me baffled as well. All new plug, coils, and wires. I swapped #5 and #6 injectors and the misfire stayed on 5. I disagree with the Ford dealer and don’t think it’s a valve spring because it’s intermittent. Any help would be appreciated.

 

no sir it still does it. i have been told that maybe there is an update where the dealer can cause the cam position sensor to re learned that could solve the problem. i haven't tried that yet. if you try and are successful please let me know what you did? Please

 

My brother is a Ford tech in Arizona and suggested the possibility of a failing cam phaser. It’s not a common issue but it does happen I guess. I take it unhooking the battery didn’t help? I think I saw that recommendation on another post.