Low fuel pressure?
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Novice
Joined: Feb 2008
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Low fuel pressure?
Looking for a little help. Just put my 04 Ultra back together tonight after a paintjob. Inside the tank is a convaluted fuel hose that goes to the "petcock" or fuel supply line. For some reason I thought I would remove the whole assembly from the tank, rather than just tape it off before we painted. So, I put regular fuel hose back on. When I went to start it, it started, rand smooth for about 15 seconds, and died. No it will not fire. I poured a dash of fuel into the throttle body, and it fired right up, and quickly died. So, it is a fuel proble. When I hit the ignition, I hear the fuel pump kick on. I assume that maybe the fuel hose is not allowing enough fuel pressure. Anyone have any suggestions? I know that fuel is getting thru the disconnect, but thats about all I can tell you. Please help. I am ready to ride.
Extreme HDF Member
Joined: Apr 2006
Posts: 10,449
Likes: 46
From: Roswell, GA
You can take a look at this link and see if your bike is throwing a diagnostic code:
https://www.hdforums.com/forum/engin...ikes-only.html
There are two convoluted tubes. If you replaced either one with regualar rubber fuel line hose, I'd suspect there is a kink in the rubber hose you used.
If you did remove one of the convoluted tubes and replace it with rubber fuel line, why did you do it?
While my bike was apart for paint, I removed the fuel tank console pod assembly to replace the fuel filter cannister. The HD kit included a new convoluted tube to connect the fuel pump to the new fuel filter cannister. If you replaced that convoluted tube with rubber gas line, a kink is highly possible in that line.
The second convoluted tube runs from the fuel pressure regulator to the quick disconnect fitting, but have no idea why that would be replaced.
Also, the Service Manual says to replace the console pod canopy rubber gasket and use 10 new screws to attach the pod to the tank. I did, but I'm not sure how not doing so would cause the problem you describe.
Hope you solve your problem.
https://www.hdforums.com/forum/engin...ikes-only.html
There are two convoluted tubes. If you replaced either one with regualar rubber fuel line hose, I'd suspect there is a kink in the rubber hose you used.
If you did remove one of the convoluted tubes and replace it with rubber fuel line, why did you do it?
While my bike was apart for paint, I removed the fuel tank console pod assembly to replace the fuel filter cannister. The HD kit included a new convoluted tube to connect the fuel pump to the new fuel filter cannister. If you replaced that convoluted tube with rubber gas line, a kink is highly possible in that line.
The second convoluted tube runs from the fuel pressure regulator to the quick disconnect fitting, but have no idea why that would be replaced.
Also, the Service Manual says to replace the console pod canopy rubber gasket and use 10 new screws to attach the pod to the tank. I did, but I'm not sure how not doing so would cause the problem you describe.
Hope you solve your problem.
just curious can you here the fuel pump quit running as in it is building up pressure?
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As I said, I removed the whole "bung" from the tank, and therefore I had to remove the tube. This is my first EFI bike, so I was not even smart enough to realize it had a quick disconnect. I was under the impression it was similar to the petcock style. I thought about a kink as well, but the first thing I did to rule that out was to disconnect it at the quick disconnect and stuck a small screwdriver up inside the takn, and fuel spilled out. And yes, when I cycle the ignition, I hear it run for a few seconds, and then it shuts off, like normal. Is there a way to check fuel pressure between the throttle body, and the tank without removing the tank? Like, in cars there is a schrader valve in the fuel rail? And, yes I used rubber fuel line, which now I see the manual says not to use. I will replace it with the OEM line, however I doubt that the whole 5 minutes it was submerged in fuel, is causing it to deteriorate and clog my injectors already.
Last edited by o3softtail; May 8, 2009 at 09:44 AM.
Extreme HDF Member
Joined: Apr 2006
Posts: 10,449
Likes: 46
From: Roswell, GA
It's a bit late for the suggestion, but buy the Service Manual for your bike. Don't know how you would put a bike back together correctly after disassembly for paint without the torque specs, for example. And the SM explains how to remove the gas tank for carb'ed and EFI bikes.
As for the problem, you didn't say if you've tried the diagnostic codes. Also, the couplings at the quick disconnect are plastic and may have been damaged or clogged with the tank removal. I have no idea, really, just guessing, since I have only worked on my own bike and used the Service Manual procedure.
As for the problem, you didn't say if you've tried the diagnostic codes. Also, the couplings at the quick disconnect are plastic and may have been damaged or clogged with the tank removal. I have no idea, really, just guessing, since I have only worked on my own bike and used the Service Manual procedure.
Road Warrior
Joined: Jun 2008
Posts: 1,282
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From: Yukon, OK
I think the first thing i would do is go get the OEM hose/quick disconnect and try it....the hose might not be pinched but it could be collapsing under pressure..which would allow the pump to shut off...that funky plastic hose that is in the is pretty ridged....so it wont squish....just my .02....i had a similar problem......and replacing the OEM hose seemed to fix it.
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Thanks for the advice. I went and bought the OEM hose....Worked like a charm. Shes alive. The fuel hose I used was all swollen and just slid off where it connects. Not sure why a fuel line would not hold up to fuel, but it dont matter. Thanks fellas.
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Joined: Dec 2007
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From: Bay Area
That convoluted line you replaced with a rubber one (if not neoprene, thats why it was swollen) is a high pressure fuel line. Fuel injection uses a pressurized tank. In cars if you leave the cap off after fueling it will die or not start. On a bike it would be dangereous to have a pressurized gas bomb between your legs, so they have a different set up where the pump takes the ambient pressure and boosts it up to the engine, a little safer this way. Its been a while since I read my book but its basic fuel injection theory