Help! Power Loss and Surging

[rlievenski4555]

While riding my beautiful red girl, I went to pass by rolling on the throttle. Surprisingly, she surged on and off power while passing. After that, I had more episodes of power loss and surging barely getting home. The gas was down to less than an 80 mile range. I also recently ran a tank through with Lucas fuel injection cleaner. The prior owner had to work on the fuel pump before buying her with 9K on her. Now she has 22K. I ordered a new bag filter from Murphs and will replace what is there as soon as I can. It would seem that restricted fuel flow from a clogged filter could cause pressure loss and surging.

FYI. The valves were checked and brought to spec this spring with 15.4K. ECU flashed. BW header and Delkavic can. New plugs added at the time. She has been running beautifully all summer.

Please let me know if I seem to be on the right track.

 

[2andblue]

I would say a couple things.

1) Fuel sock / filter - a likely culprit for sure and aligns with others’ experiences
2) Check the grounds right now. Make certain your grounds are clean and tight as this could result in a dull spark if not.
3) Your air filter has been changed I expect at your valve check? Unless totally crudded up your air filter at this mileage should not cause this but it’s worth a peek.

Note on fuel pressure - surprising with the fuel rail sensors that a drop in pressure doesn’t toss a code but again to bullet #1 several have had exact same experience as you and the sock replacement fixed it.

And BTW - those socks come off VERY dirty, it’s crazy actually…

Wayne, Carol & Blue

 

[rlievenski4555]

I would say a couple things.

1) Fuel sock / filter - a likely culprit for sure and aligns with others’ experiences
2) Check the grounds right now. Make certain your grounds are clean and tight as this could result in a dull spark if not.
3) Your air filter has been changed I expect at your valve check? Unless totally crudded up your air filter at this mileage should not cause this but it’s worth a peek.

Note on fuel pressure - surprising with the fuel rail sensors that a drop in pressure doesn’t toss a code but again to bullet #1 several have had exact same experience as you and the sock replacement fixed it.

And BTW - those socks come off VERY dirty, it’s crazy actually…

Wayne, Carol & Blue

Thanks Wayne! Fingers crossed. Yes… new OEM air filter at the time of the Valve check.

 

[Freddy]

There is no fuel rail sensor on these bikes. There is a hi pressure fuel filter shown in the DFI section of the FSM but not shown in the parts listing. It is available as a Suzuki spare part, some models of which use the same fuel pump. It's rare that this filter gets blocked but a few folks have found the only way to solve the surging issue is to replace the complete fuel pump after replacement suction socks and pump elements have not done so.

Fuel pump filters

Got a box of 49019-0013 filters in today.. as its not officially listed as a C14 part, what years do y'all know they work with? Murph

forum.concours.org

 

[rlievenski4555]

I decided to buy a rebuild kit with a fuel pressure regulator and all the O rings from The Fuel Pump Factory. Seems silly to not do it while I have the tank opened up. Will report results in a few days.

 

[Freddy]

It won't include the hi pressure filter.

 

[rlievenski4555]

It won't include the hi pressure filter.

The kit from The Fuel Pump Factory includes the pressure regulator, which is cool!

 

[rlievenski4555]

Finished the rebuild and she is running better than ever! Smooth and rapid power delivery throughout the rev range. I am super happy that it was an easy and relatively inexpensive fix.

Wayne and others were right. The filter sock and mating plate of the pump assembly were full of sludge. You can see the sock and the dried solids from the plate in the pictures.