BF egas AFR

[Damien]

I have installed a wideband oxygen sensor on my egas wagon and the first thing I noticed was it was idle/cruise AFR's hover around 14.7/1. Under WOT I see low 12's - high 11s.

I was under the impression that stoich for LPG was around the 15.6-15.8:1. Is this normal for a stock egas falcon? 

Thanks

Damien

 

[Darryl@pcmtec]

Hi Damien, Widebands do not actually measure AFR they measure Lambda and then convert it to AFR for display . Generally they assume the fuel is petrol (AFR of 14.7 is lambda 1.0). Change it to Lambda and you will see it is 1.0 and then there is no confusion.

[Damien]

Thanks for the reply, I did a bit of reading and that makes sense to me now. I'll switch my gauge to display lambda and see how I go.

Thanks

Damien

 

[Roland@pcmtec]

Definitely recommend getting used to lambda readings, it makes it a lot easier to switch fuels without having to re-calculate in your head.

Also worth remembering that a wideband measures oxygen, so if you run big camshafts with overlap you can read lean (due to oxygen in the exhaust) but still have fuel dripping out the exhaust pipe. So you have to use some educated guess work to know if what you are reading is actually what is going on inside the engine.