More silly ideas,

[Dave Zug]

yes a DP transducer.. I missed that one completely and I just got 
done programming using a half dozen of them (hvac, not car).

Then you could attatch a squeezebulb to the high side to get more 
fuel on demand.. hone in on 12.5:1 MANUALLY  ha ha ha no need to 
change fueling just have a passenger ride around with you and watch 
the O2 ;-)

sorry just a little humor

> From:          Don.F.Broadus at ucm.com

> I would think a differential pressure transducer would work. High side
> atmosphere/low side vac
 
Dave Z. www.delanet.com/~tgp