MFI too rich at idle

[chesterc]

I have a 69E with headers and am finding the mfi runs too rich especially at idle with lots of small backfires in the induction system. I think it could be that the warm air return from the standard exhaust manifold no longer exists so the mfi always operates as if the engine is cold and therefore runs rich and therefore a bit rough at idle especially. Still have plently of power and runs smooth at higher revs. Is the solution to this problem to set the mfi permanently to a warm running setting? If so how do you do this???

[tobluforu]

New MFI information Index
This might help

[chesterc]

That works for me. Some good tips here.