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Fuel System Problem

SoonerSoftail

SoonerSoftail

Active Member
A couple months ago the bike started missing just a little. Mainly during maintained engine speeds of 1800 to 3500 RPM. I raised the fuel map in that range and it worked for a while then started again. Repeat the map adjustment once more and the same result. So I knew then something was going wrong.

I've done new intake seals, new fuel pump, filter and lines, checked throttle shaft, had injectors cleaned. Regulator and the line from the disconnect to the fuel rail are the only original things left. Back to the beginning fuel map. It's much better but still not right. Guess I should have replaced the regulator too.

I have one question. With everything back together I left the fuel rail end of that line disconnected and stuck in a bottle. I turned the bike on and the fuel pump ran for a couple seconds and shut off like it had pressurized. With that line open shouldn't it just free flow fuel until the tank is empty?
 
No, the system has to sense pressure to run longer than the initial prime cycle.
If you put your thumb over the line, you'll feel it cycle again, but it will be messy, 55+ lbs. of pressure.
 
Breeze3at said:
No, the system has to sense pressure to run longer than the initial prime cycle.
If you put your thumb over the line, you'll feel it cycle again, but it will be messy, 55+ lbs. of pressure.
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Thanks. That's what I wanted to know. I didn't know if it had a "broken line" type safety.

Jeff Klarich said:
Have you done a pressure test? Take a look here. Biker Rogue's Jims Fuel Pressure Tester Article
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No I haven't. But at this point buying a kit or even gathering up all the pieces to make one it's cheaper and probably faster to just buy a regulator and have the whole system new.
 
Last edited by a moderator:
SoonerSoftail said:
No I haven't. But at this point buying a kit or even gathering up all the pieces to make one it's cheaper and probably faster to just buy a regulator and have the whole system new.
Click to expand...

Sometime it is cheaper to just buy new. Good luck and let us know what you find.
 
On my 09 EG, I had a vary slight miss at cruising speed and just once in a while. first I checked and cleaned my batt. connections. Thought that may have taken care of it till it did it again a little over 60mi later. So I ran the R's up more than I usually do hoping to throw code and it did. Ended up being a broken wire inside the sheathing right at the front injector plug. it would not miss just wiggling the wire had to give it a little tug.
Maybe?
 
mrwizz said:
On my 09 EG, I had a vary slight miss at cruising speed and just once in a while. first I checked and cleaned my batt. connections. Thought that may have taken care of it till it did it again a little over 60mi later. So I ran the R's up more than I usually do hoping to throw code and it did. Ended up being a broken wire inside the sheathing right at the front injector plug. it would not miss just wiggling the wire had to give it a little tug.
Maybe?
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I checked all the wiring when I had it apart. It will be something to go back and look at again if the regulator doesn't fix the problem.
 
Check your Throttle Body Shaft (cracked) and not only the regulator, but the plastic "bracket" that holds the regulator in place. Mine cracked and drove me crazy for a few weeks. 11 bucks. If the bracket is cracked, the regulator seal allows fuel to spew out, thus the sputtering/missing begins. Ultimately, she'll just scream for fuel.
 
When you say "lines" in your OP, are you referring to the corrugated plastic fuel lines that are inside the tank? If so, are all of them replaced now so you are eliminating the possibility of those pinhole leaks?

See here:

Harley Davidson Forums

Cheers,

TQ
 
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