Schrick 284/272 Idle

[redlightpete]

I canÂ’t get my stock piston 2.8 to idle well. IÂ’m using a Schrick 284/272 with motronic, the stock afm, and a sssquid chip. IÂ’ve cleaned up all the minor vacuum leak paths around the throttle body, but it made no difference. It idles better until it warms up, and it runs more smoothly off idle, though it feels like it has a little bit of a lean surge at low loads. It doesnÂ’t stall or hunt, and IÂ’ve gone through all the electrical checks at the ecu connector, per Bentley.

Is this cam ever going to idle well with the stock afm? Does Motronic try to adjust the idle mixture to stoichiometric based on the o2 sensor (closed loop) or can you richen the mixture as part of the map? IÂ’ve read that this cam can idle fine, but it wasnÂ’t clear what engine management or tuning were required. thanks

[Andre3127]

Do you have a wideband to check actual AF readings?

A guy I know (although haven't seen in half a decade) has the same cam in his b25 swapped 325e. I don't know whats done to it electronically, but the idle is apparently very lumpy due to the valve overlap. It's to the point where his dad (a car guy himself) told him to fix it because of how different it sounded over the stock cam. I guess the car hauls ass, though.