Is there any remedy for running rich with big overlap cam at idle? I've written a lot of opinions but is there any established "theory" supported in real life effects??
I have 95 OBD1 car, with 23X/24X 109 LSA cam. Please help as I suspect that my last rebuild was due to running constantly rich at idle and I want that rebuild to be the last one.

 

You don't know the cause of the last rebuild??????? Do you understand what will happen if you run too fat??????

I suggest you speak to these guys. http://www.pcmforless.com/

or the guys at TPIS.

 

you need to tune the computer. custom-not hand held

 

In fact - I don't know - rings gaps were much too big, but I don't know if it was due to mechanic mistake (which reassembled the enging after cam/heads exchange) or running too rich.
I had already sent emails to Ion and Bryan but no answer yet...
In fact my question is: is it possible with stock computer and closed loop to control AFR at idle?

 

Yes, to a degree, with PE idle (set %TPS for WOT to 0 at the idle RPMs, then choose idle AFR in PE tables for that range).

But if the cam is big enough it can still cause the short term BLMs to try to correct it (that can be limited too, but it also limits correction for the entire engine's range).

 

Big cams cause rich idle because they seem to cause the closed loop system to think the engine is running too lean. I've read this is due to reversion in the exhaust system.