Dashpot Control to Idle

[Bullitt5566]

I've been chasing an idle issue around for a long time. I removed the Comp Cams XE270's and put the stock cams back in. The idle issue is still there, but it doesn't stall. This allowed me to duplicate the problem and data log it.

Here is part of the problem. From idle, if I blip the throttle (first event) and rev to 2500 rpm (blue line) the dashpot (orange line) jumps and the rpm falls in a controlled manner with the dashpot. However if I blip and rev to 1500 rpm (second event) the rpm drops uncontrolled, almost stalls and recovers. The idle hunts. The maroon line is spark.

With the large cams the second event would stall, but it does not with the stock cams.

So I've adjusted the rpm error for idle control and the dashpot preposition. Neither seemed to help. I'm going to focus on the dashpot preposition now, but I'm looking for ideas.

 

[decipha]

reduce the dashpot decay rate function

.25 on down should decay 0.0007

make sure you max out the dashpot tprel max clip scalar, to 0.062

and lastely, make sure your not hitting the maximum dashpot airmass clip function as that will limit you, for good measure you can kick up the minimum dashpot xlip in low gears and max out the max clip function

details are on my website in the tuning dashpot write up

http://www.efidynotuning.com/dashpot.htm

 

[GapRider]

reduce the dashpot decay rate function

.25 on down should decay 0.0007

make sure you max out the dashpot tprel max clip scalar, to 0.062

and lastely, make sure your not hitting the maximum dashpot airmass clip function as that will limit you, for good measure you can kick up the minimum dashpot xlip in low gears and max out the max clip function

details are on my website in the tuning dashpot write up

Dashpot / EFIDynoTuning

I know this is an old post but I recognize your title decipha. I'm working with dashpot control of my Coyote and the term 'clip' confuses me. I'm used to clip meaning to limit, like clipping an audio wave to get distortion, the top of the wave is clipped flat at the limit. Can you help me understand what clip means as it relates to dashpot. I know this sounds stupid but it's got me stopped in getting a good feeling for dashpot.

 

[decipha]

coyotes dont use the dashpot functions in stock form, if u are having decel issues on a coyote more than likely you either have a different throttle body or u put a larger load on the engine for idle in any case it requires you to redial in the throttle body

go to the effective throttle area table and divide the entire first columns values by half

that column is the 0 flow base etc eta a lower value increases throttle blade opening and should reduce your issues i.e. giving u more dashpot