2001 530i, cranks, starts, dies, crank, starts, rough idle for a few seconds, dies...

[Jamieheath]

Vehicle: 2001 BMW 530i, e39, manual trans, 240K

Background: About 3 months ago it started acting up. It would not crank on the first try, but on the second try, it would start every time. Unrelated, but recently the coolant has been leaking out...but only a little over time. Then it was every few days I was adding water. So I pulled the car up on ramps 2 days ago and left it running to see if I could spot any coolant leaking. After about 4-5 mins sitting on the ramps, i heard a sound, kind of like that ball that rattles in a paint can then the car shut off.

I pushed it off the ramps and tried to start it. It would only turnover, would not start. I tried several times. Then came back later, held the pedal to the floor and cranked it. It finally started but idled rough. Then shut off. I tried again, ran rough, then stalled. Came back 3 hours later and it started right up. I revved it a few times and then tried to drive up the street, but only made it 30-50 yards and it was running rough. I turned around and parked it.

I replaced all 6 spark plugs today (as I had some lying around). Still didn't help. No lights on dash, no codes on the computer. Just turns over, sometimes it starts, sometimes it doesn't. Sometimes I can get the RPMs up to 3-4K, but most times when I push the gas it stalls.

So...you think its a gas pressure issue? fuel filter? fuel pump? Planned to get fuel pressure gauge today but autozone didn't have one on hand. Bought a fuel filter while I was there but they sold me the wrong one. So I have not done anything in that arena yet. All fuses are good. Could not find any vacuum leaks. The only thing strange is that having the front up on those ramps obviously made something odd happen while it was running at an angle. Any thoughts?

Video link https://www.youtube.com/watch?v=cgOCBPR3L5M so you can hear me try to start it and how it sounds. Oh, a belt started squealing 2 days ago too...I believe that's the screeching sound you hear in the video.

[MIKYZZ4]

Definitely check the fuel pressure first,
if found within spec, then I would check Crank Position Sensor.

[Jamieheath]

So, I replaced the Crankshaft Position Sensor. Car started on second try. I let it run for a minute and it had a rough idle then smoothed out. Let it sit for 15 mins. Came back, started right up. Backed out of garage, no issues. Drove 10 yards down my flat driveway, no issues. Revved up the engine to 4-5K RPMs, no issues. I turn out of the driveway to drive down the street (i'm now going uphill) and it starts sputtering, wont go over 2K Rpms. I stop, it idles fine. I try to drive forward again, nothing. I reverse down the hill and into the driveway, no issues. Well, I just pushed in the clutch and rolled back, but tried again and the same thing, so then I put it in reverse and it backed up without any hesitation.

So what causes it to seem fine on a flat surface, but not on the hill? I really have not tried on a fully flat surface for more than 10 yards. I have hills leaving my driveway on both sides so I can't go anywhere. Revvs fine. Idles fine. Drives poorly. Still no engine codes or lights on.

[MIKYZZ4]

Seems like the crankshaft sensor replacement eliminated your hard starting symptoms,
but driving on inclines causes fuel starvation, so I suspect #7 in the diagram:
http://www.realoem.com/bmw/enUS/show...diagId=16_0209