please help with idle surge only at slowing down to a stop, also rich lean,switch ?

[strokedcoupe]

car never had surge.. replaced lifters and found a vacuum leak on intake I had missed during original install.. fixed leak.. now has surge only on decel .. seems to start at 30mph and goes until 0mph then clears up if car hasn't died by then.. ive tried about every map I can think of in that area with no help.. so if you see something out of place chances are I have tried this and didn't fix it.. lol but any help would be appreciated.. car idles great just sitting in gear and in park

how can I change how much the rich lean swing is during idle and driving.. it does 15.2ish to 14.2ish during normal cruise on wideband.. you can feel car nose over when it swings lean it doesn't do this during ve and maf tuning so im assuming the trims are swinging it too far.. I have done wbltft and wbmaf tuning but maf needs to be done again because of few changes to cold air setup.. but is still close..

car is
6.0 lq4
ls6 intake with truck cable tb and truck mass air
cam is 571 lift 224/228 276/282
headers

[Ranger6202]

Sounds like you don't have a VSS installed.

[mowton]

From your writeup I would surmise your closed throttle idle/rolling settings have to be off as a result of the fixed vacumn leak. I would redo your idle tuning (LT/STIT, IAC settings, Desired air ect.) to start with by logging IAC steps and the other idle related PID's supported by your PCM/OS. Initially get the IAC counts at hot idle to like 40-60. You may have to lower your Desired Air as you make these adjustments. Surging is usually a result of excess fueling and by fixing the vacumn leak you should have richened the idle (as wll as off idle) AFR which was tuned using unmetered air.

Another tip, if you get the idle all zero'd in at 0 mph and you still have problems with decel, you may have to tweak the Throttle Cracker table to add or pull air in the area's you are having problems.

Ed M

Ed M

[strokedcoupe]

it does have the vss working..

Sounds like you don't have a VSS installed.

[strokedcoupe]

ok thanks ill do some logging on way home with those pid

From your writeup I would surmise your closed throttle idle/rolling settings have to be off as a result of the fixed vacumn leak. I would redo your idle tuning (LT/STIT, IAC settings, Desired air ect.) to start with by logging IAC steps and the other idle related PID's supported by your PCM/OS. Initially get the IAC counts at hot idle to like 40-60. You may have to lower your Desired Air as you make these adjustments. Surging is usually a result of excess fueling and by fixing the vacumn leak you should have richened the idle (as wll as off idle) AFR which was tuned using unmetered air.

Another tip, if you get the idle all zero'd in at 0 mph and you still have problems with decel, you may have to tweak the Throttle Cracker table to add or pull air in the area's you are having problems.

Ed M

Ed M

[strokedcoupe]

idle log, does bad at the end of log .. I wish it always did it. would be easier to pin down.. ill mess with when it cools down outside... any thing from this log stand out?