Hey gang,

First and foremost, thank you to anyone that can help me. I have had my Fatboy since it was new, have only been into a dealership to buy the bike and have it remapped when I put on new pipes. That's been almost 14 years and all had been good. Until this...

I trailered my bike to Sturgis and while up there, noticed the fuel sender was again not working properly. I decided to pop it out and see what the issue was. Didn't get to finish the job and buttoned it up. It then sat for a day during a rain storm and then another on the trailer back to Denver.

When I got it home and off the trailer, I wanted to take it for a ride to get it cleaned. As I turned on tank ignition, it was oddly quiet. Usually when I turn on the ignition, I can hear the injectors come to life with a nice electronic sound. This time, I heard nothing. I leaned down and played with the toggle to see if I was just missing something. Every time I switched from ON to OFF, I could hear what I can only describe as a slight gurgle sound come from the injectors. I tried to start the bike and nothing.

I then let it sit for a couple more days thinking that perhaps something got waterlogged from the rain storm home. Another day later, still nothing. Just a slight gurgle. Not obvious sound telling me the injectors are engaging or anything.

I opened the tank again to look at the fuel pump but didn't see anything disconnected. Buttoned it up again, and still the same results.

Has anyone experienced this before? What might I have done to cause my injectors to not engage? I've had the seat off 100 times in 13 years and have never had this problem. Can't imagine I grounded out on something.

Thank again in advance for the help!

 

What you hear when you turn the tank switch on is the fuel pump priming the system. If this does not sound right then start troubleshooting there. Anytime you are troubleshooting a EFI Harley first check that the battery is in good working order. Make sure that you have 12v going to the fuel pump, which I believe you do because you can hear it gurgling.

I would suspect that 1) There are holes in the lines inside the tank (the gurgling), 2) the fuel filter is clogged and needs to be replaced, or 3) the fuel pump is bad.

 

Thanks for the reply!

Since the bike literally ran great before I opened up the tank to try and mess with the sending unit, how could the pump suddenly go bad or the filter sudden to be full? I pulled off the sending unit 2 years ago to try and fix the fuel gauge and had no issue when I put it back together, I wonder why now.

And to clarify, when I've turned on the ignition under normal conditions, I could hear the injectors come to life right at the air filter. Now, that sound doesn't happen. I've checked fuses to see if I shorter one out but they are all good. I guess I'm of the mindset that I blew a fuse or disconnected something since everything worked fine before I pulled the sending unit off. And technically, I never got it out... I forgot how to release the spring inside and expand it to get it out.

There is no ground for the pump to the tank is there?

 

Rule of thumb:
If the bike doesn't run after you have worked on it go back to where you wee and look for what got dislodged, unplugged, or developed a leak from internal maneuvering during your venture into the tank.
Also, injectors do not come to life. The internal fuel pump inside the tank will make a whirring noise.
Remove the gas cap and stick your ear to the filler while you cycle the ignition switch.
If you hear a gurgling sound or a sound like peeing on a flat rock, you have an internal pressure leak.
Accept something happened the last time you were in there and go from there.
Bob

 

I gave you suggestions as to what i would look for based on your symptoms. FLTRI17 gave you good advice as well. That's all we can do here since we are not able to diagnose the bike ourselves.

You either have a fuel problem, or an electrical problem, possibly both. I would suspect that when you were working on the sending unit you cracked the lines inside the tank. They are 13 years old and probably getting brittle being exposed to fuel for that long.

 

Thanks guys. I had my FIL take a look at it since he's more comfortable with electrical items than I am. We tested the connection to the fuel pump and got nothing. We then tested the system relay and noticed that it appeared to be dead. From what my FIL tells me, the system relay may just do a system check before allowing the start relay to allow it to fire. What is the function of the system and start relay and is this a common issue? I don't want to just throw parts at it. And since the pump is showing continuity on a meter, we are inclined to look at the relays. Also, can a standard relay be used as a system relay or do I need to get an actual system relay?

 

Here's the latest...

-Charged battery
-Tested both relays (working)

Check Engine Light is on, but when I tried to look for codes, none were given. Still not hearing the fuel pump come on when the ignition is turned on and do not seem to be getting any juice going TO the pump. Can't seem to find a fuse that would control just the voltage to the pump. All fuses in the box are solid.

What am I missing?!?!

 

The fuel pump comes on to charge the fuel rail from a 3 second timer in the system relay. There is a back up timer in the start relay that is not used but there since relays are interchangeable unless someone put some type of generic in there.
The injectors do not fire until ECM gets 15 pluses from the crank position sensor. Once running, the ECM receives the crank position sensors signals and runs the pump all the time and it bleeds off with the pressure relief. The bankangle kill switch in the signal light and or alarm will kell power to fuelpump if bike is leaned too far.
Make sure your ECM and Fuel pump 15 amp fuses are good.
You could have broken the wire inside the tank to the fuel pump if you were rough getting sender out. Pop the console and unplug the plug going to the big plate . Put positive to O/GY terminal 1 and negative to BK terminal 3 and see if something is broke in tank if what I have said above is correct.

 

Think I got it fixed, and feel pretty stupid about it. After doing son diagnostics, I found that one of the pins in the connector to the fuel pump had bent in the connector... The ground pin to be exact. I bent it back into shape, reconnected it and everything fired right up.

Feel very lucky it was as simple as it was and something that some basic troubleshooting lead me to. But thank you everyone for the tips. I had to test a few components first and find that they worked to get me to the connector and find the bent pin.

 

Glad that you got it running again. Thanks for reporting back.