runs rough on start up
 

Hi,am having intermitant issue with the wifes golf....2010 2.5 liter. On cold start the engine runs rough,sometimes quits,unless you rev it up to clear the problem,then its perfect.Runs great,fuel consumption,power etc all good.
When I have managed to have a scan tool connected and it has done the fault,seem to get missfires on different cylinders,this morning was cyl 2,3 missfire counts,few weeks ago was cyl 1 10 missfire counts,at the moment no codes.In the past have had missfire codes on all cylinders.Has had new plugs and is the same.Is it possible to get ign coils failing like this? sporadic and only for a few seconds on start up? If it was the throttle body not controlling idle properly would it not throw codes? Driving me nuts....and I dont want any damage to cats etc as thats going to get expensive. Any ideas?????

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You need to get your motor scanned (preferably with VAG-COM\VCDS) for any error codes logged in the ecu and post them, that will save a lot of guessing.

I used vagcom on it,also used snapon scanner.December I had multiple missfire codes for all 5 cylinders.Since then there are no codes,tho I can see cylinder missfire on the data.It also usually smokes,blue and once black.I have replaced the PCV diaphragm,I had one just in case.Isuspect now the injectors are weeping,this would give me sparkplug missfires,also smoke,and my wife complains of heavy gas smell,alot more than usual on cold start up.Gonna disable the ignition,crank it for few seconds and then pull the plugs,if any are fouled wet,this would indicate injectors.

Generic scanners cover loads of makes and models they aren't specific to VAG that's why you need to find VAG-COM\VCDS that will test all components.