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?
Wow; I'm stumped. I'm guessing the engine stored no faults? As an afterthought you might email Mike Miller of Roundel's Techtalk (techtalk@roundel.org). He's typically right back at you with an idea or two....
M3 Driver: Beat you to it. I emailed Mike the same message and he came up with either leaky injectors, or the ECU. He suggested I try finding another ZHP to swap ECU's with, if I could indeed find another ZHP. Just so happens that our chapter Pres and VP both bought ZHP sedans in Imola, exactly like mine, but '04 and '05. So no problem finding another car to swap with, but haven't gotten that far yet. Forgot to mention the trusty locals put in a new fuel filter/press regulator, and new plugs because old ones were fouled. They also pulled the ICV, said it was a bit "sticky", cleaned it up and reinstalled. Runs noticeably better, but didn't fix the starting problem. I'm not buying new injectors until it's proven they are the problem, as the price is astronomical (over $105 apiece), and they get replaced all-or-nothing. I think the next cheaper option to try as an experiment is a new ICV.
Bill - Interesting. If in fact it turns out to leaky injectors I wonder what would cause that on a vehicle that new? I wonder if we can put the blame on the crappy ethanal-blended fuels that we can't seem to get away from...... Now when it comes to electronics though anything is possible these days it seems. Let us know how it turns out. cheers...
This sounds almost like a CLEAR case of leaky injectors. I get the feeling your independent did a less than thorough test. The m54 is somewhat prone to leaky injectors as is. As far as them being replaced as "all or none." I have only gone for that philosophy once and it had much more to do with a shady customer than a mechanical neccesity. It's likely that your dealer isn't sure whether the injectors were contaminated and may start to drop one by one. Replacing them all at once is just a way for them to cover their @$$ and keep you from coming back in a couple months with another problem and hard feelings. Or, they may be using the all or none to cover for their own poor diagnosis. You could always continue to drive it until the intake blows off, THEN we'll know where the problem is. Good luck.
