I put my LM-2 in and did some driving around so I can make my street-mixture (full throttle mixture was made on a dyno, now I need a tune for the everyday kind of driving). Things looked good (mostly around 13.8:1, I'm fine with being a little rich because the car has no O2 sensors and winter is coming).

Here's the thing I think might be a problem: if I put it in 2nd (for example) and hold 4000rpm (for example, any rpm will do it, though it does it more so above 3000rpm) and then take my foot off the gas, the mixture goes to the high 16s to the low 17s. As the car decelerates it will richen up to the mid 15s. Is this a problem, or is this what I should expect when my foot is off the gas? I can't just richen the off-throttle mixture because the mixture is set in terms of engine manifold vacuum and rpm. The engine manifold vacuum is 0.5 bar with my foot off the gas or when cruising, so foot off the gas and cruising have to share the same fuel distributor control pressure.

 

normal, car is sucking air back through the tail pipe making it look lean. its fine

 

Good deal. e10 stoich is 14.1:1 right? So leaving it such that most of the time I'm at 13.8 isn't really wasting a ton of gas, is it?