HI guys,
I have searched and searched to no avail. Bike is a 2002 Fatboy injected. I got new tins this winter and had to remove the fuel pump from the old tank into the new. No issues before the swap. Now when the switches are turned on the pump comes on but it sounds like it's half power compared to the obvious fuel pump sound before. I know for sure its getting power and kicking on. I can hear the relay and hear the actual pump come on it's just about half the sound of normal and not pumping enough to start. During the swap the pump assembly was out of the tanks for about 2 weeks, is it possible it dried up and I need a new one? Any idea appreciated.

 

The period of time the pump is on for cranking should not change.. If the pump sounds weird, I'd pill it out and check for leaks. When you swapped parts between tanks, what clamp did you use for the hose that goes to the bottom of the tank? It's also possible to bend or tweak the regulator/ filter components and cause a leak.. Check electrical connections. Being careful, you can pull the air filter and squirt a little fuel down the intake.. A good cough can blow gas and flames out the intake tho..

 

Almost sounds like a ground issue and is ground looping to run the pump, albeit low power.
Just a guess,
Bob

 

Thanks for tips. Here is what I've done so far. Pulled pump assembly out far enough to see into the tank. No leaky hoses or bubbles but also no fuel flow. Pulled pump assembly out and bench tested in fuel, it pumped and flowed like it should. Put back in tank, no flow. Bench tested again and great flow. I should note the bench test includes running fuel through the filter and regulator. Back in the tank...no flow....
3rd bench test now it won't flow on the bench.
Oh and this is a new pump.
I left the garage very frustrated!

 

The bench test was directly from a 12v source. The battery on the bike is at 12.5 V but when I check the power to the pump assembly I'm at 11.9ish.... Maybe the pump is weak because it's not getting the full 12V.

 

How do you tell there is not fuel flow? How do you tell there is fuel flow?

Is it possible the valve at the bottom of the tank is not working?

 

With the internal hose going to that valve disconnected there is no flow. Bench tested there is flow

 

Is it possibly you have the polarity of the pump wires wrong?

 

I will check but the plug harness only goes one way. I will say with the multimeter common on the ground wire at the pump assembly wire harness plug it showed -12v.... ground the common on the frame or battery it shows +12v.... that was early on in diagnosing... would that indicate a bad ground?

 

Yep.. Could also be crossed wires somewhere..