My 08 NIghtster is popping while down shifting ,i cant stand it.it is really annoying. Im running my 08 Nightster 1200 with vance and hinse short shots, vance and hines fuelpak, and a roland sands intake.i run it very clean with 93 gas with a octane boost or a intake cleaner everyonce in a while .i called vance and hines they just keep giving me the same codes for the fuelpak,does anyone have a solution for this?or anyone else run into this problem?

 

Call V&H customer service again.
I have an FLHTC (Iknow, different engine, but same concept)
They have been very helpful with my popping on decel.
They told me to go to "mode 23" and lower by one and try it.
(It even explains this on their website)
If still popping lower another one.
Keep lowering by one until the popping stops.
I lowered "mode 23" by one, 3 different times.
The popping on decel has now stopped.
V&H CS has been VERY helpful for me.
If you're running 93, not sure why you're adding an octane boost, it's not necessary.
Good Luck.

 

Thank you steve

 

Decel pop is generally caused by raw fuel igniting when it hits the hot exhaust pipes. The conditions that cause the perfect situation for this need to be changed, either by making the decel fuel richer, or leaner. It can be either, believe it or not. Generally the solution is to enrichen the fuel mix up, just to change the conditions to make them unfavorable to ignition. Your fuelpak does not allow you direct access to the decel enleanment map, but it sounds like V&H has a mode that adjusts this as Steve has indicated.

One thing I do not understand about the Delphi EFI system is why they don't just cut the fuel delivery off totally on decel - BMW does this and it works just fine. Why throw gas down the pipes if it's not being used to propel the bike? Cooling is the only reason I can think of as the bmws are water cooled. Anyone have a better answer?