Does adding timing effect air fuel ratio?

[Kdubslugga]

I just installed an Auto Meter wide band and Im ready to do a little tuning on the car. All im wondering is, if i mess around with the Timing option on the PMS adding a few degrees at different RPMS, should my Air fuel ratio run leaner and let me know when there is to much or to little timing in it? Sorry if this is stupid, better safe than sorry.

 

[Repostyle]

The simple answer... no

The long answer... No, the air and fuel are drawn in on the intake stroke, the valves close and begin the compression stroke then the spark is on the power stroke. So no matter when the spark happens, it's already drawn in all the fuel and air it's going to.

 

[Kdubslugga]

Makes sense man, thanks for the reply

 

[87coupe50]

but what if the timing is adjusted to where the entire fuel mixture isn't being completely burned? (too far advanced or retarded) an in-complete burn would have left over fuel which would have an affect on AFR

just a thought...

 

[HISSIN50]

To answer what I think you're getting at, it can affect the reading on a gauge

 

[1990MustangLX50]

You are changing when the air fuel mixture is ignited thus effecting how it is burned therfore yes it will effect a/f.

 

[MFE92]

Yes, it absolutely affects the A/F that the O2 sensors pick up, or put another way, it absolutely does affect how lean or rich the engine behaves.