choinga

Just got my car back from the shop (head gasket job plus some other "WYIT" stuff...) and damn in runs good!

I had the guys put in a Lindsey gauge cluster - boost gauge and the air/fuel meter gauge. The AFM is super cool looking... digital dots that go in a circle...lean...stoich...rich...

Toodling around it bounces from all the way lean to mid/high stoich...at boost it's always mid/high stoich to rich (which is green)...which I'm guessing is good.

I don't know much about this one - figured I'd put it in since I thought having a gauge cluster with one boost gauge and a MBC would look kinda silly.

What exactly is this gauge telling me??

Thanks in advance!

xsboost90

should read stoich during idle- 14.7:1 air/fuel mixture. On boost you should be seeing it go rich- around 12-13:1 prob. green on the gauge- when you let off the gas it will probl. jump to 21:1 or way red since the injectors are closed and you are seeing almost no fuel and lots of air. You should always be in the green - > stoich while you are on the gas. If you are into it and you see red or higher than 15:1 LET OUT!

choinga

awesome...thanks. That was my intuition but was looking for a more 'technical' answer.

Wikipedia to the rescue: http://en.wikipedia.org/wiki/Air-fuel_ratio_meter

krystar

optimal AF while cruising should be 14.7 parts fuel to 1 part air. optimal AF while in boost should be 12.5:1

if your AF guage is like mine, the 4 or so LED's at the middle "stoich" are yellow. the ones in green are "rich" and the ones in red are "lean". even if you're boosting and you see it flicker into yellow, lift off gas immediately.

choinga

thanks...when cruising mine just kinda bounces and stays in the lean to stoich area...and yes it's LED's. It really never gets green during cruise but when I lay on it - it definitely moves in that direction and stays there.

That's what I was looking for really...what actions should I take depending on what the gauge is telling me. Thanks!

My mechanic liked the one that I bought from Lindsey so much he ordered one to put in his 944.