S52 OBD2 Fuel Pressure Regulator?

[cmeptb13]

Can someone please clarify these questions:
-For early OBD2 fuel rail, such as a 97 528i, does the feed line hook onto the top part of rail? Since the bottom part is where the FPR is. It makes sense but it'd be nice to get a strait answer.
-Secondly, the loss valve. Is it necessary to run the engine or is it more of a luxury feature?
Don't mean to hijack the thread but since this topic has come up. Thanks.

[drulle]

Can someone please clarify these questions:
-For early OBD2 fuel rail, such as a 97 528i, does the feed line hook onto the top part of rail? Since the bottom part is where the FPR is. It makes sense but it'd be nice to get a strait answer.
-Secondly, the loss valve. Is it necessary to run the engine or is it more of a luxury feature?
Don't mean to hijack the thread but since this topic has come up. Thanks.

I have the same questions, could someone please help, thanks.

[justin_l_]

1. Fuel feed should go into the rail, the return should come from after the regulator.

2. Running loss valve can be removed and flashed out of ecu.

[drulle]

^^^ thanks, I'm not sure if Dave flashed it out or not

[Northern]

2. Running loss valve can be removed and flashed out of ecu.

Bump from the dead for any information on this. Hoping it is similar to disabling EWS/muffler flap with a single control bit, but I can't find any information on it.

Deleting the running losses valve because I'm running an M50 manifold, and want to run a larger rail/lines/pump.

[BlackSpeed66]

Also interested in this for my s52. Will be running an m50 intake but also keeping OBDII. Just pulled the fuel lines on the m20 today, among other things - hoping to yank the motor out next weekend!

[Northern]

Bump from the dead for any information on this. Hoping it is similar to disabling EWS/muffler flap with a single control bit, but I can't find any information on it.

Deleting the running losses valve because I'm running an M50 manifold, and want to run a larger rail/lines/pump.

I posted up on the romraider forums. Apparently this should be listed under the Diagnostic Trouble Codes (DTC) list in Romraider, but I didn't see it.

It makes sense for this to be on the DTC list and not a control bit like EWS, because unlike EWS, the ECU isn't looking for information from the Running Losses 2/3 way valve, only sending it information on how much to open to allow fuel to bypass the fuel rail "loop" (at least from my understanding.) The ECU doesn't change anything based on this valve. It only throws code P1145 ("Solenoid Valve Running Losses Control Circuit Electrical") for diagnostic purposes.


After checking some other sources of MS41 DTC lists, it appears it may be DTC 50 on the list, but somebody with a running car will have to test to confirm.

I'll post again if this turns out to be correct.

[Northern]

^
Confirmed Post 869 here