Need help with long crank to start after driving and parking

[plasstik]

I have an 06 4.4 with 142k on the dash that gets 16-17 city/ 20-21 highway. I figure this info would be useful to know.



Issue,
At first, after fueling up I would need to crank, turn off, repeat and then my X will start. This situation presented/s 95-99% of the time. Ok not too bad. I can could still drive it like i stole it. No stalling, great pedal response, no other issue. That would be a lie, there are many issues with these old BMWs. Besides that.



A the beginning of 2023 that issue got worse. I drive, park for 15-60 minutes, and I would need to crank, turn off, repeat. Still no stalling, spuddering, great pedal response.


Parts changed (new from eeuro, bmwpartsdeal, fcpeuro, getbmwparts, some OE, some OEM, a couple of well known names)

- gas cap
- Leak diagnosis pump
- Dust filter
- Hose (connects to dust filter)
- Fuel Tank Breather Valve
- Fuel filter with pressue regulator

- fuel pump

- refurb'd injectors from eeuro
(All installed this month)


Cleared the codes, she started right up, no issues. (she does that after being parked for a long time)


Codes haven't come back, (yet) but after driving, and parking, I still need to crank, turn off, repeat, then she'll start. Again, runs fine.



I don't let the starter just turn until she starts because it's not (I don't believe so) an ignition issue. I cycle the key on and off, as to prime the system with fuel, and then she starts right up, no issues, and runs like a cheetah. Well, like a cheetah with 142k on her.



What am I missing?
What part needs to be replaced to keep/allow fuel pressure to remain in system?
Would changing the charcoal canister help?



Do I need to think outside of the fuel system to solve this issue?


If it's computer stuff, that's out of my scope of practice. If I can do a valve stem guide replacement, then I can fix this.

[X5chemist]

If fuel pressure remains stable, I would check the crank and cam sensors. Gunk can build up on them. Wire damage may also be possible.

[plasstik]

Originally Posted by X5chemist

If fuel pressure remains stable, I would check the crank and cam sensors. Gunk can build up on them. Wire damage may also be possible.

Ok. But in the beginning, the issues only presented after refuel and no other time. Would that be a precursor?


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[X5chemist]

The fuel filter could be restricting flow. I don't see it on your maintenance list. If fuel pressure needs another prime, pressure would be slightly lower at first crank.

[plasstik]

Changed that too. This month


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[Henn28]

Have you tested vacuum yet. The soft hoses tend to deteriorate badly with age, in places that are difficult to see, and can create all sorts of problems.

[plasstik]

Originally Posted by Henn28

Have you tested vacuum yet. The soft hoses tend to deteriorate badly with age, in places that are difficult to see, and can create all sorts of problems.

I have not even thought about that. Is there a specific place to start?


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[andrewwynn]

The symptom says fuel pressure not staying. Usually if the check valve in the pump failed.

[getty150]

Yeah that's my thought as well the check valve located at the fuel filter...it can be replaced located beside the fuel pump...thinking of replacing mine soon!

[plasstik]

Originally Posted by andrewwynn

The symptom says fuel pressure not staying. Usually if the check valve in the pump failed.

Fuel tank was clean as well as the old filter on the fuel pump.