I have a 2003 E46 330i ZHP sedan with about 55,000 miles on the odo that has a startup problem. Here are the symptoms: 1) In the morning, the car will start with a simple twist of the key (usually). However, it belches a considerable cloud of un-burned fuel out of the tailpipe. Once started, the car runs just fine. 2) In the late afternoon, some 8 hours later, or anytime after having run long enough to warm up, the car will only start if I crack or pump the throttle while cranking. Once started it runs rough, as if it's not running on all cylinders. After a long while this clears up, but it's faster if I clear the problem by gently revving the motor; after a few seconds everything seems to back to normal again. Other than starting, the car runs normally. So the pattern here seems to be starting somewhat normally, but belches raw fuel, when the motor has "rested" overnight, and the air temperature is cool to cold (typical winter and spring mornings in upstate NY). After being started that way, it will only start with considerable applied throttle, and again belches raw fuel, even after sitting all day, regardless of air temperature. So far a solution has eluded both my dealer (where the car spent two days before I needed it back) and my trusted local BMW repair shop (where it has already spent 3 days, and counting, as I write). The dealer found no vacuum leaks, tried swapping in a new mass-air sensor and cold-start valve, to no avail. They speculated it might be leaky injectors, but I needed the car back. Trusty local independent BMW shop picked up where the Dealer left off, checked the injectors and found them to be ok, changed the spark plugs, all to no avail. What do you think is going on here?