[Hoody007]

Edit: solved by changing the fuel pressure regulator.


Hi all,

Creating this in the main section for visibility, but let me know if I need to move it to the N55 specific area.

I have a 10/2011 build N55 335i. Has the factory PPK tune on it. For the last week or so, I've been experiencing intermittent long cranks. HPFP seems to be the latest revision.

The long cranks started out as a bit of a longer start (maybe ~3 sec), and have progressed to a ~15 sec long crank most recently. It does not happen every time, though.

I have noticed that the long cranks correspond to when the fuel pump has not primed when unlocking / opening the door. So, for example, if I start the car after it's been sitting overnight, and the pump primes, the car fires right up. But if it's been sitting for, say 6 hrs, and the pump hasn't primed, then I get the long crank.

The car has always started. Pulls nicely to redline. I've never seen a warning light on the dash, either a SES or yellow 1/2 engine light.

ISTA does not show any codes (like a phantom, there but not). I can't get INPA to read the N55's DME.

Here's the readings from ISTA, after the car has been sitting for an hour.

The "high pressure" value fluctuates when the car is off - seems to start to trend lower.




Reading online, I'm inclined to replace my fuel pressure regulator. My car does not have a low pressure sensor on the fuel rail.

I'm at a loss beyond that, and would truly appreciate any guidance.
Thank you all!