cold rough start

[arsen]

hello i have a 325 model 2001 convertible..the problem with my car is almost every morning when i start the car it starts perfect but when the rpm is coming down to 6000 the car begins to shake and the check engine light turns on...i turn the engine off and when i restart it sometime it runs normal..and when i put it on scanner it give a combustion failure at cylinder 5 and combustion failure at cylinder 3...and sometimes for ex i drive thecar for half an hour and i park it..and when i start the car after half an hour a PUFFF sound comes out of the engine i guess thats the misfire and teh car donnt start but the i retry it ir runs but the rpm level drops down to 5000 several times (rough start)and then the car is somehow normal..
any idea guys for this problem??i like my car and dont want to sell it..bcz off this issue..theres no air leakage ive changed the crank sensor and some parts too..

[brettski]

The Air flow sensor can throw some funny issues, try disconnecting it and see if it has any impact on the issue (you will be down on power but the engine should run ok).