So after thinking my battery had been somewhat low lately (the odd chime here and there, auto dip-mirrors working intermittently, etc.) I went ahead and bought a new 850cca battery and put it in, still nothing. So I had it towed home and commenced to pulling the back seat and checking the fuel pump. It would not come on, even when cranking, so first off I replaced the fuel pump relay and checked the fuse before buying and installing a new fuel pump. After the install, the new pump comes on and runs fine, but still no start, just crank crank crank...I then pulled the airbox and sprayed a little carb cleaner in the plenum, and every time I do, she fires right up, but only until the sp;ray is used, maybe 2-3 seconds. I checked for spark after pulling a coil pack with the plug inserted, and had spark. I then leaned moreso toward a camshaft position sensor, thinking I would have no spark at all if the crankshaft position sensor was the culprit, so I replaced it with a new one, Still no start.

My next thoughts are possibly low fuel pressure since I didnt change the filter, or a bad regulator (since I got a buddy to crank the engine after pulling the cap off the filter assembly and I was able to easily hold the pressure and it was spraying from the bottom of the filter assembly near the regulator) so I am planning on getting a fuel pressure gauge and checking for >47psi. The only other thought was possibly the crankshaft position sensor, even though I have some spark. I am stumped on this one, has anyone else ran into something like this? ANy help would be greeaaatttllllyyyyy appreciated, thanks.

Sorry for the book, but wanted to be as throrough as possible, also wanted to mention there were no codes before the battery change, and there have been none pop up since all the cranking after the battery change/during this nightmare troubleshooting...

And I noticed the beginning was cut off of the original message, I started with everything had been running fine, I stopped at a store about a week ago only to come out to no start, it would crank and crank, but no start. That’s when I changed the battery and the rest is history...

Did you replace the pump or the filter? Or both? Go to the fuel rail, remove the cap an press on the relief valve, does it itspray fuel ? No need to know yet if it's 47lbs, I'm betting no fuel, I had same symptoms on my 04 530. Do you have fuel in the tank?