Cold start misfire / rough idle

[Mrthemike]

I've had a flashing/steady CEL on cold start for a while now. Usually runs fine after the engine seems to "warm up".

Spark plugs replaced about 3k miles ago
Ignition coils replaced today (all 4)
Ran a bottle of Techron Fuel System Cleaner with my last tank of gas

Showed a code of misfire in cylinder 4...

Any other ideas or is it time for the stealership?

Thanks!

 

[omeydz]

I had a similar problem with my golf, turned out it was a fuel injector jammed open.

Change the injector on the misfiring cylinder

 

[The Fed]

You within the drivetrain warranty? Take it in. Bad idea waiting - you could have fuel in your oil.

 

[loccusst]

I had this and did a couple of things. Changed plugs, replaced the coil packs, cleaned intake valves, replaced cam follower, and replaced the water pump. Replacing the water pump seemed to finally do the trick but I was also throwing a code for the cooling system as well.

 

[dubbin415]

When this happened to me, I had a flashing cel on cold start ups, and the cel never went away for like a year. Misfire cyl 1, constantly. Turns out i had to clean my intake valves. Once I did that, the misfires and codes never came back, and the car runs like new!

 

[Elwood]

Happened to me as well. As it turned out, it was a clogged fuel filter. Too many fuel stops in BFE, I guess. The pump would run when I turned the key, but couldn't get enough fuel past the filter to feed the HPFP. No problem when warm or even if I shut it off cold and restarted. 1st start was a bitch, though.

 

[MARCUS GTI]

When this happened to me, I had a flashing cel on cold start ups, and the cel never went away for like a year. Misfire cyl 1, constantly. Turns out i had to clean my intake valves. Once I did that, the misfires and codes never came back, and the car runs like new!

What codes did you have? I'm getting a P310b ....ive done plugs, coils, fuel sensor on the hpfp and fuel filter...still the same.