hunting and flat spot at 1200 rpm

[Holden202T]

the afr target is not the issue, the issue is that at that rpm the engine has less or more vaccum than the standard cam so it moves the motor into a different part the the ve table than it would normally be in.think of it more as the ve table is how much air the engine flows at x y load point, change the cam, port the heads, better flowing exhaust, this all means there is different air flow at x y load point, so you need to tell the computer what that new number is so then it can use its calculation to work out how much fuel to put in.

[Dylan]

Thanks for that, cant wait till I get all my gear sorted and do some tuning.

[vlad01]

the afr target is not the issue, the issue is that at that rpm the engine has less or more vaccum than the standard cam so it moves the motor into a different part the the ve table than it would normally be in.think of it more as the ve table is how much air the engine flows at x y load point, change the cam, port the heads, better flowing exhaust, this all means there is different air flow at x y load point, so you need to tell the computer what that new number is so then it can use its calculation to work out how much fuel to put in.

So its just a matter of adjusting the VE table so that the AF table corresponds to the actual WB output over the given AF points on the table?

[Holden202T]

have a look at the red link in my signature below, has all the information explained in there how to do it.

[vlad01]

cheers! didn't know of that document, now I understand heaps better now.

[Holden202T]

maybe need a brighter or larger red ?

[hot308vb]

i had the exact problem with my clubby, after a few weeks a big flat spot would appear and id find a few downward spikes in my ve table so i would fix that up & go for a few more weeks till it did it again untill i figured it was the ve learn causing them, i disabled ve learn and havent had a drama since.
maybe give that a try!

[VL400]

Were they in the same spot and same value?

[Holden202T]

actually when I first did testing of VE learn for VL400 I found I was getting similar issue, I raised the minimum rpm for ve learn to work

[Dazza92VP]

Yea that's what I did smoothed out the ve table and turned off ve learn