[ianrich511]

Hello all,

So here is why I changed my Fuel Pressure Regulator.

Car would take 5-10 seconds to start when cold(whether that be 15 minutes to a couple days).
Cranks were still very strong.
Car started every time.
If I killed the engine, and tried to restart, it would fire up immediately.
Car ran fine otherwise.

If you are having these symptoms, then it might be your Fuel Pressure Regulator. I have read so many threads about what it could possibly be and using logic I took a shot that it was the FPR and was right. I am not saying this is for sure the problem to the symptoms. Perform at your own risk.

This takes about 3 hours, but is not technically difficult. The replacement piece I bought was from ECS tuning, here is the link the the FPR unit EDIT: I found the O-Rings in the bottom of the box, but I have already finished the job and dont know if I will be putting in new rings as the old ones looked and felt fine.

Also, I will not be fully writing the procedure as most of it is better documented then I have time for.

First, do everything in this article up to Figure 10. In figure 10 you can see three main lines all with arrows pointing to them(Two red, and a green pointing to the connector). These are the lines that come from the FPR unit. Do not secure them with mechanics wire as you will be pulling them out of the driver side of the car. Do everything in figure 10 up to 'pull the fuel pump module out of the car'.

Now,

On the driver side, there is a matching cover. Unscrew the four bolts. Pull off cover. Disconnect the electrical connector. Disconnect the fuel line(just pull hard on the tube at the neck with pliers, it will come).Take a punch and hammer and get the ring off.

A note on the ring. Spray it down with WD-40 before attempting to hammer it off. You can put the nozzle under each little raised piece to coat it all the way around. This is the hardest part of the entire operation, if you can do this, you can do the rest.

You will notice the unit will try to lift out, thats because there is a spring on the unit. Pull up on the unit, wiggling side to side. It fits in there perfectly, and there is a perfect way out so don't be forceful. I had to reach my hand in and grab the hoses when I was pulling which made it easier. Once the unit is out, pull the lines through. Be careful, this is where you will most likely get fuel in your interior.

With the unit out, celebrate, the rest is easy.

Prep the new unit. I zip tied the three lines together at the very end(on my second try) because on the first try they were going different ways and getting stuck when trying to fish them between the two tanks. Also, take out the plastic cap on the line that connects to the fuel pump(I did not and had to fish it out of the tank).

Feed the lines directly in the middle of the two holes(Fuel pump & FPR holes), there is a valley there. I went most of the way with the lines in the driver side and then reached in to grab them from the fuel pump side. Once you have the lines over and in site you can put the FPR fully in. Make sure you line up the tab on the units top ring into the slot so it is seated flat(shown in pelican parts figure 11 for the FP but it is the same design on the FPR). Screw down the collar, and hammer punch it tight. Reconnect fuel and electrical line to the FPR.

Go over to the fuel pump side, and pop the two lines in the two slots(which one goes where doesn't matter) and connect the line with the head until you hear the pop. Reconnect the main fuel line from figure 9. Put the top of the module back into the pump(there are two brass rods that go in the sides of the pump to align it). Once everything is sitting flush, screw down the collar. Hammer punch it tight, reconnect fuel lines and electrical connections. Cover FP and FPR. Put back seat back in. Reconnect battery.

Now when you start the car, it is going to take a second as there is no fuel in the FPR unit. When it starts it will be rough for a little. Let it settle. When it is idling smooth, bring RPMs up to about 2K and hold just to get all the bubbles out. Turn it off, and then back on to just make sure.

I tested mine at 30 minutes, 1 hour, and will again test at overnight but it hasn't repeated the symptoms for the first two tests.
EDIT: Tested this morning, started right up.

Enjoy a quick start! If you have any questions, just let me know.

[cdeason]

I just did this and I cannot get the fuel line to completely seat in the fuel pressure regulator. Any thoughts ?

[GearMeister]

Thanks for posting the detailed instructions with links to the parts.

My '07 328xi has the exact same symptoms. Tested the fuel pressure which holds steady right around 70psi with the engine running but bleeds down to 5 psi within 15 seconds of shutting engine off. Already replaced the fuel pump with a brand new one but that didn't help.

If I restart the engine right away, it starts right up but if I wait a few minutes I get a long crank. It always starts though, just takes 3-6 seconds and makes you wonder if it will start.

Here's a link to a short video I made showing the pressure build up and bleed off in case it's helpful to anyone else in diagnosing the problem.

I'll post an update after changing the regulator assembly.

[GearMeister]

Update: I installed the new pressure regulator and the car fires right up now! The fuel pressure holds steady now after the engine is shut off.

[GoRomeo]

Thanks for sharing

[nukezero]

I had the same exact issue at 124,500 miles. I replaced the FPR and car fires up like a champ now.

[BennyDee]

Awesome write-up. Thanks for the write-up.

I had long cranks and a gas smell with my car, and a new FPR fixed it.

I noticed when I opened that port to the FPR, there were little cracks on top of the assembly and a small gas leak.

[hardr85]

I am attempting this tonight. I was wondering how the two black hoses connect to the fuel pump are released? Do you have to push anything to release them or do they just pull out? It is hard to tell from the pictures.

Update- did this last night, I realized they just sit in the clips, just had to pull straight up on hose.

[Yangorang]

Did you notice any other symptoms other than just the harder to start when cold?

[GoRomeo]

You guys can always try the Techron Fuel system cleaner. Its worth a shot for only $10.00 or so.

[Tempxst]

You sir may be a life saver for this write up.

I posted a thread months ago looking for answer to this issue on my 06 330i (N52) and I even gave up testing it myself and took it to a mechanic who said his tests couldn't confirm which of the million things it could be.

This is making me a lot more certain my assumptions of a failing FPR. I have the EXACT same symptoms and will be ordering and installing mine this weekend.

Thanks again!

[xavi718]

Originally Posted by Tempxst

You sir may be a life saver for this write up.

I posted a thread months ago looking for answer to this issue on my 06 330i (N52) and I even gave up testing it myself and took it to a mechanic who said his tests couldn't confirm which of the million things it could be.

This is making me a lot more certain my assumptions of a failing FPR. I have the EXACT same symptoms and will be ordering and installing mine this weekend.

Thanks again!

that was your problem ? did you solve it ?

[bman142]

I replaced mine today. This video was key:

2008 E91. Took about an hour. I had a micro crack in the dome of the FPR. It's a common issue. Driver side left side rear smelled of gas. A look underneath showed some gas stains. Not drips but wet. A couple of important notes:
1. I bought the special tool on Amazon for $25 to remove the metal ring. I still had to bang it a few times and put some WD40 in to loosen it up before I could get it to move. I bought the FPR from FCP Euro.
2. It's a pressure system, so remember to run the car until it dies AFTER you disconnect the wires, before you disconnect the fuel lines. Have a throwaway towel ready it will spill a bit when 1st removed on FPR side.
3. I drove the car down to about 1/16 tank before starting. Definitely helps.
4. Wear gloves and goggles. Gas in the eye is not good. White vinegar removes gas from hands.
Any questions, just reach out.

[GoRomeo]

I replaced mine a few weeks ago and my fuel gauge is not reading the correctly. It only goes up to a quarter and put $40 of gas. Should be at around half of tank. ACcording to a few YouTube videos we will have to check the fuel pump side to see if all connectors and hoses are connected correctly. Anyone else had this issue?

[arjvnv]

Originally Posted by ianrich511

Hello all,

So here is why I changed my Fuel Pressure Regulator.

Car would take 5-10 seconds to start when cold(whether that be 15 minutes to a couple days).
Cranks were still very strong.
Car started every time.
If I killed the engine, and tried to restart, it would fire up immediately.
Car ran fine otherwise.

If you are having these symptoms, then it might be your Fuel Pressure Regulator. I have read so many threads about what it could possibly be and using logic I took a shot that it was the FPR and was right. I am not saying this is for sure the problem to the symptoms. Perform at your own risk.

This takes about 3 hours, but is not technically difficult. The replacement piece I bought was from ECS tuning, here is the link the the FPR unit EDIT: I found the O-Rings in the bottom of the box, but I have already finished the job and dont know if I will be putting in new rings as the old ones looked and felt fine.

Also, I will not be fully writing the procedure as most of it is better documented then I have time for.

First, do everything in this article up to Figure 10. In figure 10 you can see three main lines all with arrows pointing to them(Two red, and a green pointing to the connector). These are the lines that come from the FPR unit. Do not secure them with mechanics wire as you will be pulling them out of the driver side of the car. Do everything in figure 10 up to 'pull the fuel pump module out of the car'.

Now,

On the driver side, there is a matching cover. Unscrew the four bolts. Pull off cover. Disconnect the electrical connector. Disconnect the fuel line(just pull hard on the tube at the neck with pliers, it will come).Take a punch and hammer and get the ring off.

A note on the ring. Spray it down with WD-40 before attempting to hammer it off. You can put the nozzle under each little raised piece to coat it all the way around. This is the hardest part of the entire operation, if you can do this, you can do the rest.

You will notice the unit will try to lift out, thats because there is a spring on the unit. Pull up on the unit, wiggling side to side. It fits in there perfectly, and there is a perfect way out so don't be forceful. I had to reach my hand in and grab the hoses when I was pulling which made it easier. Once the unit is out, pull the lines through. Be careful, this is where you will most likely get fuel in your interior.

With the unit out, celebrate, the rest is easy.

Prep the new unit. I zip tied the three lines together at the very end(on my second try) because on the first try they were going different ways and getting stuck when trying to fish them between the two tanks. Also, take out the plastic cap on the line that connects to the fuel pump(I did not and had to fish it out of the tank).

Feed the lines directly in the middle of the two holes(Fuel pump & FPR holes), there is a valley there. I went most of the way with the lines in the driver side and then reached in to grab them from the fuel pump side. Once you have the lines over and in site you can put the FPR fully in. Make sure you line up the tab on the units top ring into the slot so it is seated flat(shown in pelican parts figure 11 for the FP but it is the same design on the FPR). Screw down the collar, and hammer punch it tight. Reconnect fuel and electrical line to the FPR.

Go over to the fuel pump side, and pop the two lines in the two slots(which one goes where doesn't matter) and connect the line with the head until you hear the pop. Reconnect the main fuel line from figure 9. Put the top of the module back into the pump(there are two brass rods that go in the sides of the pump to align it). Once everything is sitting flush, screw down the collar. Hammer punch it tight, reconnect fuel lines and electrical connections. Cover FP and FPR. Put back seat back in. Reconnect battery.

Now when you start the car, it is going to take a second as there is no fuel in the FPR unit. When it starts it will be rough for a little. Let it settle. When it is idling smooth, bring RPMs up to about 2K and hold just to get all the bubbles out. Turn it off, and then back on to just make sure.

I tested mine at 30 minutes, 1 hour, and will again test at overnight but it hasn't repeated the symptoms for the first two tests.
EDIT: Tested this morning, started right up.

Enjoy a quick start! If you have any questions, just let me know.

Hello, late reply but I’m going through this right now. I have just changed the FPR and upon starting, the car started up instantly and was running for about 30-45 seconds when the rpm’s started twitching up and down shakily around 1-1.5k rpms, I made the mistake of not gassing it as well to keep it alive. The rpm’s car then started getting weaker until it died again. This was right after changing the FPR as a result of a gas leak in which we identified the FPR as the problem. Ever since have tried starting it to no avail. The starter just keeps going but no turn over and engine has yet to start again.
Unsure where to go from here, debating opening rear up again to check connections of hoses etc, and then will test fuel pressure as well to see if maybe it’s fuel pump, although don’t think it is. We just changed the FPR which was the problem and it did start so now just trying multiple things to see why its not starting. Any help would be great thank you again.

[KieranB1996]

Fluid controls might have a pressure regulator that might work - https://www.fluidcontrols.co.uk/

[cdgatti]

You can buy the part on Amazon: Delphi FT4054 for about $350.

[BimmerNiels]

High pressure sensor. Hello friends. Have a bmw e91 from 2009, which occasionally takes a long time to start. With Bosch tester, it has written error on high pressure sensor (rail sensor) have tried 2 times to replace it with aftermarket models. The first time the car went into emergency mode, the tester said transition in sensor, the second time the car tried to start and the tester showed nothing. When I reinstall the old sensor the car starts and runs. Have ordered an original sensor now.
Anyone with experience?