power fc lumpy idle

[JAMMA]

Anyone know how to cure this? Checked for any vacume pipes being loose etc but all seem fine.

Jamie.

 

[neil240z]

are you running aftermarket cams?

 

[campbellju]

What is your AFR and ignition timing when its lumpy?

Is it less lumpy once warm?

I've seen a couple of cars mapped over rich at idle.

 

[Fusion Ed]

Common that, quite often the scaling is incorrect so although may be ok on boost, its not at idle. Another case the car had 1000cc injectors and the power FC was simply not able to give a small enough pulsewidth at idle to get a good afr reading.