Hey all,

Figured I'd share and post this quick DIY for anyone who may have to replace this little sucker on their 03-06 E55. I started smelling fuel under the hood, it was faint but it was definitely there. Usually went away after few minutes of driving but any fuel smell = no good in book. Upon further inspection, all the injectors were clean and dry which led me to smelling around the rest of the fuel rail. The smell was coming from the throttle body area. Finally, i felt dampness on the bottom of the fuel pressure damper and decided to replace it as the o-ring was probably dry and letting fuel seep by.

I purchased the new FPD (P/N 1120780092) from the local dealer, along with a new retention clip for about $70. I would recommend a new clip as the original was noticeably more spread open due to its age.

Here is the install (few pics attached below):

1. Lift the hood to service position (full 90* angle)

2. Remove airboxes and the Y intake

3. Remove 4 torx bits holding the throttle body in place. T30 if my memory serves me correctly.

4. Remove the lower PCV hose bracket from the TB and set it aside (dont drop it like I did) and pull the PCV hose out of the TB.

5. Set the TB aside. *This is a good time to clean your TB by the way!

6. Set a few rags under the TB and under the FPD as you will have some fuel spilling. I did mine after the car sat overnight so it was a bit less fuel. If you are starting with a hot car, make sure to de-pressurize the rail by relieving pressure at the fuel rail schrader valve on the front of the passenger side valve cover.

7. Finally ready to attack the FPD. Using a large flat-head screw driver, pull the clip out (towards the firewall). It should come out fairly easily.

8. With pliers, slowly remove the FPD out of the rail. Wiggle left to right ever so slightly, you dont want to damage the rail. Mine came out with very little effort.

9. Have the new FPD near. Put a dab of oil on the o-ring, and slip the new FPD in. Using a lever, ensure the new FPD goes all the way into the fuel rail. I used a large flat-head and leveraged against the blower.

10. Install the new clip.

Then reinstall all items in reverse order. Remove rags. Once all done, i ran some water around that area to make sure all the fuel is washed away.

I hope this will help someone! Cheers.

Jut curious, could a faulty FPD cause any noticeable issues at idle or in drive? What would be a tell tale sign of a faulty one other than a fuel smell?

the FPD can also clog up over time and be dirty, which can cause drive ability problems.

Is there a part number for that clip or does it come with the FPD?

Sorry, just seeing this now. I'm sure there is but I don't know it. When I got the FPR, i just asked the counter guy at the dealership to include the clip as well.

Gonna try to do this myself...

You got it man. Remove the box and the throttle body to give yourself access. Other than that, its easy. Just make sure to put a dab of oil on the o-ring and seat the regulator correctly.

PS - I'd recommend having a friend start the car as you watch for fuel leaks.

You mean like after I reinstall it?

I've never removed a throttle body so this'll be a first for me, but if I can do it without shidtting my pants maybe I can do an upgrade later on. Been watching a lot of vids on how to remove the sc pulley too so I might do the upgrade myself

Yes, after you are done.

TB is very easy to remove. Literally 4 bolts and that's it. Dont even worry about unplugging the plug, just set it aside. And be sure not to drop ANYTHING into the blower, maybe stuff a clean rag into the hole just to be safe. You can cause serious damage if you drop something in there. So just cover it so you dont have to worry about it.

Regarding the pulley, see how this goes first. If this is a breeze, attack the pulley next. I'm always here to help so if you are in a pinch, shout me a holler.

The time is coming that I need to do this... I have a stupid question please don't laugh.... fuel pressure regulator and damper mean the same thing, no?

You’re all good man. And yes, same thing.

Well... not exactly. The fuel pressure damper is just a little spring loaded canister to smooth out the pressure pulses in the fuel rail. A fuel pressure regulator is for setting the maximum pressure and maintaining it. I don't think we have one of those in the system.

Yeah I'm not so sure, a mechanic told me it needs changing while discussing the supercharger overhaul. Maybe he used the wrong word for it- I don't know.

I thought the fuel pressure regulator was attached to the bottom of the (in tank) fuel sender? Go to 3:26 in the video posted below.

Thanks, That makes sense having the regulator right there under the filter. Overpressure can just bleed out into the tank again.

Doing this on my G55 w a M113k motor in it.

Here's what you'll need for anyone else going this route to solve this issue, which normally happens in colder weather (the o-ring contracts on the Damper)

305-997-03-45 Fuel Injection Throttle Body Mounting Gasket
112-078-00-92 Fuel Pressure Regulator/Damper
00112-141-13-80 Gasket
000-984-81-61 Clip

Hoping for a break in the weather so I can get this sorted.

sry for hijacking old thread - but I think it’s a good tip to preventatively replace your FPD in your m113k equipped cars



mine disintegrated!

the middle section crumbled away as the membrane and spring compressed and decompressed…

resulting in on/off rough idle caused by slowly clogged injectors…

finally misfire cyl #1 & #5 appeared and I knew something was not right.

best regards

Amen! I made a video not too long ago when I replaced mine.

https://mbworld.org/forums/c219/8443...ml#post8854888

@nd-photo.nl Andy, what else was required while you were replacing the fuel pressure damper? Any gaskets or o-rings? (injectors, surge tanks, etc.) Any issues with broken or crumbling connectors on the fuel injectors?

I‘m not Andy, but I‘ll answer it for him 👍🏻

Fuel Injector O-Rings, plastic washers and meshs are always good to have instead of needing these.

Fuel injector connectors - if old - are brittle and should be replaced.
Buy 9 of these - the camshaft sensor has the same connector and gets old too.

Surge tank and throttle body gaskets are cheap and should be replaced after your repair on the injectors/fuel dampener are successful and leak free.

While you are „in there“ replace the plug beside the throttle body (brake booster connection for non SBC cars) and the rubber grommet/seal below it (for the crank case vent system)

Throttle body should be cleaned as well.

That should be all 😇

best regards

@HubTraum That's a complete answer

I already serviced the injectors (O-rings & filter baskets). Surge tank gaskets I need to renew, I have been reusing them every time till this day. As I don't measure the boost pressure, I don't know if I have a leak I will put them on my list for this year

Waiting for my damper to come in. Was going to just weld the hole closed but figured I might as well just replace it.

Why would you weld it close? It has a function

In all the engines I have built and raced I never had run a damper and never saw any fuel fluctuations on each injector EGT or AFR readings in the data logs. But every engine also had a return fuel system with an Aeromotive regulator which dampens fuel pressure waves in the rails.
My current system in the car now is Two Walbro pumps with all the stock in tank parts,beyond the fuel level sensors,bypassed or removed.
A #8 fuel line to the fuel rail with an inline filter,looped fuel rail with a center inlet to the rail and side inlet welded closed and an Aeromotive fuel regulator set at 55 lb's pressure with a #6 return line to a Radium Fuel Syphon in the tank.
So I don't believe I needed the damper but left it in anyway for the hell of it. Dampers for E55's are on national back order so if I can't get one I will remove it to prevent any future issues with it but again I am no expert so I will leave it in since the engineers thought it was needed....who knows !

Crystal clear