misfire when cold QP 2009 4.7S

[mcm66]

Had car for a month but in last week problem when first driving away in morning.
Car starts without misfire, idles and will rev without misfire, but as soon as I accelerate misfires badly for a couple of seconds then everything ok and pulls away smoothly.
If I take off very gently it's ok, the faster I accelerate on moving away the worse the misfire. Only happens after sitting overnight and only for a couple of seconds.
Any one got any clue? I'm 200 miles from a dealer although could get someone local to see if any codes have been recorded. No lights on dash as a result though.

 

[safrane]

MAF issue?

 

[c4sman]

Coil packs on a 2005 Porsche Carrera S caused this for me a few years ago. Gradually got worse over a few days before they were replaced.

 

[Gixerboy]

Suggest :-
1) check for air leak on EGR valves ( passes hot air from exhaust back into inlet during warm up)am air leak here will make it run weak on warm up, hence the hesitation on light throttle..
2) clean throttle body butterfly, - a ridge is carbon forms on the edge of the butterfly & can cause roughness when moving from closed to light throttle.
3) & replace plugs if not already done.

These items do not throw up fault codes in the early stages.

Hope these pointers help

Cheers

Dave

 

[mcm66]

Thanks all, I'll post what the solution was when I get time to get it looked at. Regards, John