[bbowden]

2009 335d, full delete, BRR tune, 60K.

Having scoured the forums and NABDOG, I'm looking for a second opinion on a 4560 fault. On Testo logs I can see actual pressure dropping from desired, rail pressure control valve closes completely and the flow regulation valve opens fully but high pressure pump doesn't seem to be able to keep up. Or one of the valve actual positions is wrong. Screen shot and log file in attached google doc folder.

https://log.tunezilla.com/s/9orcZaBX

https://drive.google.com/drive/folde...L4?usp=sharing

ISTA+ passed my rail pressure sensor(rail pressure goes to 0), flow regulation valve(+-20bar desired setpoints) and rail pressure control valve(shuts down engine). All injectors passed resistance test. Attempted to read the fuel rail pressure sensor with oscilloscope to determine pump issues but got too much noise to be useful, it's a cheap scope, also in the google doc.

Thinking it must be the HPFP, any other ways to test or what Oscope to people use? Any ideas are appreciated.

[335dlci]

Stock pump? I have a source for r90s...

[Owen81]

You didn't mention maintenance but I assume you changed your fuel filter before going this deep into the electronics?

"Low Rail Pressure! Codes 4560, 4570 and more for BMW Diesel - Rail Pressure Plausibility delivery controlled" https://www.tunemyeuro.com/low-rail-...ry-controlled/

[bbowden]

Interested in a r90, want to make sure the HPFP is the culprit, ideally before I purchase one.

Should've mentioned, fuel filter was the first thing replaced.

[maryjane]

Originally Posted by bbowden

Interested in a r90, want to make sure the HPFP is the culprit, ideally before I purchase one.

Should've mentioned, fuel filter was the first thing replaced.

Pm me....for info from Ryan....he lost his phone.

[bbowden]

Teed in a fuel pressure gauge before the HPFP, getting a repeatable 53PSI at idle, wonder if I need to do some pulls and see it it keeps up.

Edit: Think I figured it out, did a ghetto injector leak off test (water bottles with equal length nylon tubing). Injector 3 is by passing about double the quantity of the other injectors at idle about 4 minutes. Is this a tale tale sign or should I get them tested?

[Yozh]

How old is the FCV. And have you ran the parameters for LPFP. 53psi May be ok for idle but I would run duty, voltage, current, rpm parameters. They should run in the 70 to 80 psi range. In fact there is no hard and fast here. No tuner modified EKP maps. And X5 vs E90 run a bit different. I would see what your lpfp is doing in driving. Obviously you are loosing rail on shifts. To me it looks like either a delivery issue (inclusive of FCV), or the Hpfp. Somehow my bets are on delivery. Also pull your injection rate parameters.

[robnitro]

That's very little for 4 minutes, mine were around that with number 2 having more. It means we have very little leak back. Don't worry about number 3.
I forgot the spec of how much is too much but this is way below that. 👍

Originally Posted by bbowden

Teed in a fuel pressure gauge before the HPFP, getting a repeatable 53PSI at idle, wonder if I need to do some pulls and see it it keeps up.

Edit: Think I figured it out, did a ghetto injector leak off test (water bottles with equal length nylon tubing). Injector 3 is by passing about double the quantity of the other injectors at idle about 4 minutes. Is this a tale tale sign or should I get them tested?

[bbowden]

Turned out to be a dirty fuel tank and LPFP.
I cleaned out screen on the original pump, reinstalled and ran it to pick up the rest of the dirt. Replaced the pump and it’s good to go.