What a/f is your idle
 

Hey everyone I can't get my A/F down at idle. Currently it's around 12-13 any attempt to reduce the fuel leads to the car stalling out all the time. I have a ported motor and my idle is around 900-1000. I just thought I would try to find out what other people's A/F ratios are at idle.

Raven

My street ported FD likes 12.5 -13.5 on a cold engine with ambient air temp <80F and about .5 leaner at ambient temps 80-100F. Once the engine is up to temp, I can easily run 1.0 richer.
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That's NORMAL!
These engines like rich idles.


-Ted

Most all engines like rich idles. Rich being a term relative to stoich. The air speed is slow enough that fuel falls out of atomization and isn't burned properly.

14.5 is bad?

It just means your wide-band sensor needs to be changed. :)


-Ted

12.5-13

Idle on a rotary can be set sometimes anywhere between 13-14, but i have seen 13B turbo engines that dont even like part load at 13.5 AFR, and foul up.

Also, ambient conditions play an inportant part in that too.

13.0 should be fine for most conditions, runing the ilde in the 12's in traffic will probably fowl the plugs faster then usual.