Lean cruise

[0081(2)]

I nearly have my tune dialed in now and i want to start looking at the lean cruise table but im not too sure on what the data means or how to use it.

The table is called Lean Cruise - Air Fuel Delta Vs RPM and CYLAIR, can someone explain how to use this table.
Most of the data in it is 0.00 or 0.70

Thanks Pete

[Holden202T]

So in the case of .7 I think you will find when it's at that point the commanded afr of 14.70 it is 14.70 + .70 = 15.40 commanded afr!

[vlad01]

when I use this function, the target AFR always read 16:1, might of been 17:1 ?, and pretty sure the table had the default 0.7 delta?

[vlad01]

yeah, it was 17:1. with lean cruise enabled, just looked at my old videos.

[VL400]

Are you sure it had a 0.7 delts default? The deafult I thought was 2.3 on early V6 bins, so works out to 17:1 target (probably a little too lean and can be fine tuned).

[vlad01]

you are probably right on the default values.

17:1 is fine, I reckon you can go even leaner than that.

[0081(2)]

What are the conditions for lean cruise to enable ?? all i can see is a temp enable but im guessing there is some time limit or something like that.

My stock bin varied from 0.41 to 2.31 will need to do some tests to work out where its happy

[The1]

lean cruise is pointless in most cases, you may save 0.1L/100 but that's about it, 15.4:1 is touted as the best AFR for a complete burn. Non flash pcm's have a timeout since idle to enable lean cruise, as well as coolant and speed. Flash PCM's have the same but the timeout is in a table.

[vlad01]

from my calcs, 8.6% less fuel usage when its active which more of less reflects what I observed when using it, I adjusted the parameters so it comes on a lower road speed and the timeout much shorter so I could use it more often.

[Holden202T]

yeah that was one thing I changed too, made it come on earlier after a stop.... I honestly didn't spend too much time on it other than some fine tuning of the settings due to different thermostat etc in my car ...