• You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will see less advertisements, have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact us.

Fuel Pressure Fault code

Buellxb Forum

Help Support Buellxb Forum:

G

Ggeezer

Well-known member
Joined
Aug 14, 2017
Messages
50
Location
Victoria, British Columbia
Hi again, not been here for a while mostly because my bike has been running well and I spend most of my time riding it. Recently, I turned on my key and the CEL came on for 3 seconds and went out as it should and then it came back on and stayed on. It didn't matter if the bike was running or not the same thing happened every time I turned the key on. I pulled out my trusty Buelltooth and phone and checked the error codes, there was only one "0 Fuel Pressure Fault". That's what is wrong as far as the ECM is concerned but the bike runs perfectly otherwise, it starts cleanly every time, runs at all engine speeds as it should and handles full throttle bursts as it should.

What I have done to the bike over the years, replaced the fuel pump, replaced the fuel rail pressure sensor. I checked the fuel pressure when the bike is running with ECM Droid and it hovers between 40 and 50 psi. A little research revealed that the fuel pressure should be tightly controlled at 49 to 50 psi and if that is true would probably be the reason I have a CEL.

I am wondering what you guys have to say about this. Have any of you had any similar experiences? Have you got any ideas on how to fix this issue and permanently clear the code.

Running my bike under these conditions does not seem to have had any negative effect so I guess I can just put a piece of black tape over the CEL if I can't sort this out since having the CEL light on all the time isn't really telling me much anyway :)

Anyway, here are the bike specs:

2010 Buell XB12Scg
 
I didn't know the 2010's got a fuel pressure sender. Thats cool. It can't be for tuning so it must just be there to turn on the CEL if theres an issue... like yours is doing. Same with the 1125's, they were all DDFI-3 as well.

Anyway, yes, it should be at 49psi and rock solid, even at WOT. I would recommend a COMPLETE fuel pump re-build kit that includes the pressure regulator and hoses (they get pinholes). Contact Barrett on here or Rev-Mo.com for high quality kits and stay AWAY from the e-bay stuff, it's terrible.
 
Cooter said:
I didn't know the 2010's got a fuel pressure sender. Thats cool. It can't be for tuning so it must just be there to turn on the CEL if theres an issue... like yours is doing. Same with the 1125's, they were all DDFI-3 as well.

Anyway, yes, it should be at 49psi and rock solid, even at WOT. I would recommend a COMPLETE fuel pump re-build kit that includes the pressure regulator and hoses (they get pinholes). Contact Barrett on here or Rev-Mo.com for high quality kits and stay AWAY from the e-bay stuff, it's terrible.
Click to expand...

That's the thing, I rebuilt the pump a while back and all was good until this code was thrown. I also went to the trouble of installing the original pump and the results were the same. I have since put the new pump back in (getting really good at that by the way, in and out in under 45 min.) I guess its possible that I have 2 faulty pumps and pressure relief valves but... The thing is, the fueling system on these bikes is pretty simple and I can't really see where it could be going off the rails here. There are no leaks visible on the outside and unless the pump housing is cracked or maybe a dirty injector is spitting fuel into the intake all the time I don't know what else it could be.

As for the fuel pressure sender switch on the fuel rail, I believe that was a 2010 only thing and it is there to tell the ECM when to cycle power to the fuel pump so that it is not running all the time. Prior to 2010 I believe the pumps just ran all the time and relied on the pressure relief valve to bleed off pressure if required.
 
There is a U-shaped outlet hose from the pump that is internal in the tank. That hose likes to get pinholes and leak internally in the tank, it gets worse and worse until its not enough to feed the regulator and the pressure drops from the rock solid 49 psi its supposed to have until:

"the fuel pressure when the bike is running with ECM Droid and it hovers between 40 and 50 psi" which is PROOF there is something DEFINITELY wrong with the fuel supply. I know you don't want to do it again, but that failed test is PROOF there is something DEFINITELY wrong with the fuel supply.

IMO it's sure worth 45 mins to find out. Those hoses are very special and should come in a complete re-build kit. Take it out, stick the pump assembly in a bucket and jump it to a battery, plug the end, you'll know right away.

Hope that works for ya:up:

edit: Whats you AFV? I'm betting it's nowhere near the neutral 100 it's supposed to be because it's been compensating for low fuel pressure.
 
Gord: Got your PM and email address and thanks. I'll respond this morning. On your pump situation:
The 2010 XB pump is unique to that year. Easily identified by the large metal "W" shaped clip holding the regulator to the housing...large black plastic motor shield...wiring harness unplugs from the pump body itself. The pump is unique to 2010 XB models and as you mentioned, fuel delivery system also unique to 2010. Pump is cycled on and off by the ECM receiving pressure readings from the fuel rail sensor. All prior XB pumps charge the system with key and kill switch on...then shut down till engine starts...then run continuously. Your pressure sensor is simply telling the ECM that the rail pressure is substantially below minimum, signaling the CEL...the stored fault code...the pump to run near continuously. You have either a faulty pump regulator or pump motor, or both.

You stated pump "replaced". With what???? If it was rebuilt by a novice with online Quantum parts, therein lies your problem.
 
As an eBay Associate we earn from qualifying purchases.
As an eBay Associate we earn from qualifying purchases.
34nineteen said:
What about this? Seems like a quality product and the seller is a stand up, American patriot (not to mention smart and handsome) from Leola, PA.

https://www.ebay.com/itm/1757181300...jzm86p+PEbmZaH4xVfcgPE+lSk|tkp:Bk9SR96w2-aAYg


Not some hippie living in his El Camino in El Segundo.
Click to expand...

That stuff is ok. They use Viton that has been mined from the peaks of the Allegheny mountains, carefully transported through only the best covered bridges by hand-built Amish wagon train and then refined in the cauldrons of only the finest of churners.
 
As an eBay Associate we earn from qualifying purchases.
Cooter said:
There is a U-shaped outlet hose from the pump that is internal in the tank. That hose likes to get pinholes and leak internally in the tank, it gets worse and worse until its not enough to feed the regulator and the pressure drops from the rock solid 49 psi its supposed to have until:

"the fuel pressure when the bike is running with ECM Droid and it hovers between 40 and 50 psi" which is PROOF there is something DEFINITELY wrong with the fuel supply. I know you don't want to do it again, but that failed test is PROOF there is something DEFINITELY wrong with the fuel supply.

IMO it's sure worth 45 mins to find out. Those hoses are very special and should come in a complete re-build kit. Take it out, stick the pump assembly in a bucket and jump it to a battery, plug the end, you'll know right away.

Hope that works for ya:up:

edit: Whats you AFV? I'm betting it's nowhere near the neutral 100 it's supposed to be because it's been compensating for low fuel pressure.
Click to expand...

Cooter,
If by "U shaped hose" you mean the corrugated translucent white flex hose that came with my rebuild kit then that was replaced at the time of rebuild about 2 years ago. I can easily pull the pump (since I'm such an expert now ;)) and test it as you suggest.

Questions,
When you say "put the pump in a bucket and run it off a battery" do you mean I should run it at least partially submerged in gasoline? I assume that I will need to find some way block off the pump outlet so that it will build up to at least 50 psi too, correct?
 
Barrett said:
Gord: Got your PM and email address and thanks. I'll respond this morning. On your pump situation:
The 2010 XB pump is unique to that year. Easily identified by the large metal "W" shaped clip holding the regulator to the housing...large black plastic motor shield...wiring harness unplugs from the pump body itself. The pump is unique to 2010 XB models and as you mentioned, fuel delivery system also unique to 2010. Pump is cycled on and off by the ECM receiving pressure readings from the fuel rail sensor. All prior XB pumps charge the system with key and kill switch on...then shut down till engine starts...then run continuously. Your pressure sensor is simply telling the ECM that the rail pressure is substantially below minimum, signaling the CEL...the stored fault code...the pump to run near continuously. You have either a faulty pump regulator or pump motor, or both.

You stated pump "replaced". With what???? If it was rebuilt by a novice with online Quantum parts, therein lies your problem.
Click to expand...

Hey Barrett,

I replaced the original pump with one of your kits back in July 2020.
 
Last edited:
Ggeezer said:
I will need to find some way block off the pump outlet so that it will build up to at least 50 psi too, correct?
Click to expand...

The fuel pressure gauge will work as an effective way to block off the outlet and read pressure too. Use your existing fuel hose from the pump to the rail to connect the gauge/block off.


Back in 2021, Barrett was using pumps built by slave labor brought in from oppressed countries that he traded with the overlords for spices and Gros Michel ("big Mike") bananas. These pumps were assembled in the fiery depths of Lancaster county, where Barrett (formerly "user-deleted") ruled supreme with an iron fist. At this time, the "great uprising" and oppressed people struck back against the mighty Pennsylvanian and he was banished to the land of Mid-Atlantis where he now runs a motorcycle company. Granted, during this time pump quality was a bit off due to unrest with the workers. If he would have only kept that vending machine stocked, this could have all been prevented. Damn you!
 
Last edited:
Ggeezer said:
Cooter,
If by "U shaped hose" you mean the corrugated translucent white flex hose that came with my rebuild kit then that was replaced at the time of rebuild about 2 years ago. I can easily pull the pump (since I'm such an expert now ;)) and test it as you suggest.

Yes, but thats a good sign that it's new

Questions,
When you say "put the pump in a bucket and run it off a battery" do you mean I should run it at least partially submerged in gasoline? I assume that I will need to find some way block off the pump outlet so that it will build up to at least 50 psi too, correct?
Click to expand...

Yes, but water is fine. Stick your thumb over the end and it will build pressure enough to check for leaks in the system. The cause of the 40-50 psi wandering is what we are looking for. A sp[lit regulator body, leaky connection or hose, etc, because if you were losing pressure somewhere else, it would be leaking on the floor.

I'm not sure it's true, but even if the 2010 fuel pump is a pulse-width modulated pump and the fuel pressure sensor controls it. It should still be a rock solid 49psi because theres no way to tune a fuel map correctly with inaccurately varying pressure.
 
Okay, I fixed it. It was the flex hose which was leaking at one of the hose clamps.

I tested it in a bucket of water with a piece of plastic tubing placed over the fuel pump outlet that had a very small hole in it to let some water pass. I hooked the pump up to a variable power supply that I have and ran the voltage up slowly to 12.5 volts. The leaks became very apparent very quickly so thanks Cooter for the tip. An added bonus is that I was also able to test the regulator at the same time which I can now confirm works perfectly.

I was able to use a short piece of .25 ID rubber fuel line instead but now there is interference between the pump and the inner part of the fuel tank/frame. I was able to squeeze it in there to test but I don't like that it had to be forced in there so I will probably order another flex hose from Barrett or someplace local if I can. At least I was able to get it to clear the fault code which makes me very happy.

Thanks again guys.

This forum is invaluable to a hack like me. Without it I probably would have junked this bike years ago.

Cheers, Gord
 
Glad that worked out:up:

Importantly, regular fuel hose is NOT rated to be submerged in fuel and will disintegrate quickly:/ Check that the hose you used is rated for that:eagerness:
 

Similar threads

S
2009 Buell XB12SCG, Runs rough when warm
Replies
16
Views
13K
Barrett
Barrett
K
new guy
Replies
0
Views
16K
kdad
K
J
1125r Fuel Pump Fuse blows, even before the fuel pump should be priming.
Replies
1
Views
9K
Barrett
Barrett
K
2003 Buell XB9R codes 13, 14, 15, and 16
Replies
2
Views
3K
Barrett
Barrett
R
2009 XB12R -Wiring Issue? Need Help
Replies
5
Views
7K
Barrett
Barrett

Latest posts

Back
Top