My mk3 vr is developing a random misfire when it's cold outside if I go any more than half throttle, it misfires for about a minute then stops and goes back to running smoothly? It also has a problem with cold starting as the revs drop to around 200 an it either stalls or goes back up to idle speed? I am thinking this could be something to do with oil not getting around fast enough on start up? Any ideas will be appreciated!