My 740 turbo is having some problems on the start. Car starts up fine, but I always let it sit for about 2 mins before putting it into gear or it will stall once it goes into gear- (been like that forever). However, it now shuts off in these 2 mins that its sitting in park. It will usually start up again with no problem. Once on the road, the rpm gage is all over the place, i might be going at 3,000 rpm, all of a sudden it will fall to 0 for a sec (almost seems like its gonna die as ur driving), then will go back up again. The problem goes away after about 5-10 mins after the car reaches operating temperature. Does anyone have any suggestions or ideas about what the problem might be?