99 rk. pcIII, trueduals, se heads, se 258 cams. just ahd dyno tuned. a couple weeks ago. hevent ridden much since. there is now a popping on decel. fairly regular. where to start. any suggestions?

 

There are at least two kind of decell pops I have found. Now this is just me and I am not sure which FI you have but the process and idea is the same.

One-- when you let off in a normal fashion, maybe downshift for a turn, and it pops slowing down.
that is the low RPM thing too rich. The tune, if there is a way to cut the Volumentric efficency in the--- low RPM closed throttle area. Say below 2500 RPM and Zero throttle. Think about this now, this is what the throttle is when doing this.

The other popping, ---more like aloud backfire out the exhaust, during shifts sometime or let off after a high RPM run, I have got rid of by "increasing" the Decelleration. )Talking about this right here gets my mind crazy, Increasing the decrease).

This part of the program does its thing just for a second or two but what it does is cuts, real quick, the fuel to the engine. Which you want to do anyway while you shift. Then you can increase the increase to make up for this as you get it back on..

Quiet, smooth shifts.

 

Although we do not tune EFI here, we have attended the PC Training Courses.
Dan Burkes that taught the classes, alert us there are 2 ways to cure the decel popping.
Starve it, or drown it.
He suggested that fuel starvation is better.
Scott

 

I kind of like the sound myself.