Alien OEM Fuel Pressure Regulator pulled from 03' M3

DavidU86 · 10-04-2012, 07:14 PM

Changed the fuel pressure regulator today. I am perplexed because the one I pulled out of the car is a Bosch 3.5 bar not meant for the S54 engines (#0280160597). I've never noticed any ill effects; I am second owner, and picked up the car at 17k miles (Currently at 52k). I dyno'd it shortly after I got it with only a Borla muffler (Installed by previous owner), and it put down 278 rwhp on a mustang dyno after 3 runs in about 72F at 2600' elevation.

The FPR I just put in, is the correct 5.0 bar meant for the S54 (#13531404089). I've tried researching this, and it seems that the 3.5 bar FPR I pulled out never should have been on the car. I have all the maintenance records from previous owner, and of course the FPR (or anything fuel related) was ever touched.

Any explanation for this? I'm concerned running the new 5.0 bar FPR will induce some issues.

Thanks,
David

illestminimike · 10-04-2012, 10:59 PM

That's random dude.

DavidU86 · 10-05-2012, 09:12 AM

Driving around with the supposedly correct FPR (5 bar), the car seems to have lost quite a bit of umph; the idle catches itself way down at 200-400rpm every time I left off; throttle response is delayed. Overall, everything smells rich. LTFT shows -9%/-11%; STFT jumping from +2% to -6%. Throw the incorrect 3.5 bar back in?

~David

DavidU86 · 10-05-2012, 02:10 PM

After only another day of driving (~15 miles): LTFT are now at -12/-13%. I think I'm going to throw the 3.5 bar (Incorrect FPR) back in. This is so strange.

~David

DavidU86 · 10-05-2012, 02:33 PM

3.5 bar back in; all resolved.

Close/delete thread.

~David

Mallee · 10-07-2012, 08:26 PM

I wonder how much the engine management would have to relearn after a fuel pressure change?

I've no suggestions on what you should do though.

10-04-2012, 10:59 PM	#2
illestminimike Registered User Join Date: Jan 2012 Location: West Covina CA Posts: 3,924 My Ride: 2003 SMG Vert M3 View My Garage	That's random dude. __________________ -2003 M3 Vert -1967 Mini Cooper

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10-04-2012, 07:14 PM	#1
DavidU86 Registered User Join Date: Jul 2007 Location: Phx, AZ Posts: 10 My Ride: 03 M3 View My Garage	Alien OEM Fuel Pressure Regulator pulled from 03' M3 Changed the fuel pressure regulator today. I am perplexed because the one I pulled out of the car is a Bosch 3.5 bar not meant for the S54 engines (#0280160597). I've never noticed any ill effects; I am second owner, and picked up the car at 17k miles (Currently at 52k). I dyno'd it shortly after I got it with only a Borla muffler (Installed by previous owner), and it put down 278 rwhp on a mustang dyno after 3 runs in about 72F at 2600' elevation. The FPR I just put in, is the correct 5.0 bar meant for the S54 (#13531404089). I've tried researching this, and it seems that the 3.5 bar FPR I pulled out never should have been on the car. I have all the maintenance records from previous owner, and of course the FPR (or anything fuel related) was ever touched. Any explanation for this? I'm concerned running the new 5.0 bar FPR will induce some issues. Thanks, David

10-05-2012, 09:12 AM	#3
DavidU86 Registered User Join Date: Jul 2007 Location: Phx, AZ Posts: 10 My Ride: 03 M3 View My Garage	Driving around with the supposedly correct FPR (5 bar), the car seems to have lost quite a bit of umph; the idle catches itself way down at 200-400rpm every time I left off; throttle response is delayed. Overall, everything smells rich. LTFT shows -9%/-11%; STFT jumping from +2% to -6%. Throw the incorrect 3.5 bar back in? ~David

10-05-2012, 02:10 PM	#4
DavidU86 Registered User Join Date: Jul 2007 Location: Phx, AZ Posts: 10 My Ride: 03 M3 View My Garage	After only another day of driving (~15 miles): LTFT are now at -12/-13%. I think I'm going to throw the 3.5 bar (Incorrect FPR) back in. This is so strange. ~David

10-05-2012, 02:33 PM	#5
DavidU86 Registered User Join Date: Jul 2007 Location: Phx, AZ Posts: 10 My Ride: 03 M3 View My Garage	3.5 bar back in; all resolved. Close/delete thread. ~David

10-07-2012, 08:26 PM	#6
Mallee Registered User Join Date: May 2010 Location: Melbourne, Australia Posts: 392 My Ride: 2002 E46 M3 View My Garage	I wonder how much the engine management would have to relearn after a fuel pressure change? I've no suggestions on what you should do though.