I have a 2003 3.0i Z4. I have had problems in the past when starting the vehicle. When starting it(only after it has sat overnight or longer) the rpm's jump up with the injected juice from the starter to about 1.5k -1.75k rpm's like normal and then drops down to idle and goes too low. It goes down to .75k rpm's or lower. A few days ago, the car literally died when i tried to start it. The next time i started it, it did something like a pulse from .75k to 1.25k and back down 3 full cycles and then leveled out at 1k rpm(the one and only time the pulsing has happened). I ran into problems about 3,000 miles ago and the vehicle wasn't starting at all. Just whining and turning. I had the batteries cold crank amperage tested and the voltage tested. The battery is good. I replaced the starter, which was what had failed to make the car not start....but i am still left with nagging issue. It is not extremely common but happens often enough to show some attention. What else could be causing this?