Sorry to be responding to an old thread but many who may have the same question might be reading this thread for the first time.


The Dyno-Jet PV-2 website has this to say:
Deceleration or shift popping:

"To address decel or shift popping, use the built in Power Vision feature Quick Tune. Start by adding fuel (+5), and spark (+3) in the decel columns, and then test. Adjust further if needed"



I don't know but thinking these guys probably know what they are talking about.

 

I agree that it does require >additional< fuel... which cools down the exahust gases... which of course hits your mileage when you spend a lot of time doing in town riding. Each exhaust system is different, however.

I had a power commander and to get mine to work without dumping fuel all the time I got a TMax... which at the time allowed me to make the adjustments in the right places.

 

decell pop is your friend... And it's cool

 

Decel popping gotta love it

 

I've had good success on several bikes by auto/smarttuning to get the VE table correct, then setting the AFR to stoich and (if necessary) advancing the timing a little. There's no load under these conditions, so no danger of damage from pinging. I just can't understand the logic behind dealing with excess unburnt gas by adding MORE gas.

It's a shame you can't push the ECM out of closed loop at high AFRs. Because without the EGR table (or equivalent), you can't account for reversion, which is what pushes the the VEs (and the adaptive fuel values) up in this region and causes the additional of extra fuel.

 

Sounds legit. Thinking I might send your omment to Brian at Fuel Moto to see if he can use it

 

I would think some tuners would have DFCO (decel fuel cut off). For this to work, it cuts fuel at a certain MAP vs RPM and introduces fuel once another condition is met.

 

This is exactly what you need to cure the decel pop... not more fuel. Adding more fuel is a wasteful work around.

 

The exhaust pulses are, on many systems, used to help remove unburnt fuel (which there will most certainly be on decel) and to help pull in more fuel and air during valve overlap. The pop occurs because there is enough air in the exhaust pipe to allow the unspent fuel to ignite which the heat in the pipe will do (i.e. no spark is required). If you reduce the amount of air, the fuel won't burn. If you increase the amount of air you create a lean condition which has issues in and of itself. That's the logic... better ECMs allow you to provide the correct AFR for any conditions... but that isn't what everyone has. HD, especially on earlier EFI bikes, has their setup basically hard coded in to handle their products... not peformance exhaust systems and air systems by vendors.