improving idle afr

[multiplex]

my car currently is idling at around .76-.8 lamba.

i can't seem to get it to idle any closer to 1, or the car dies out.

in my VE table, i have the idle area set to 11. If i change these to 10, the car dies.

Should i be concerned about this?  What could be done to help the car idle less rich?

[Sprocket]

Whats the ignition advance at idle?

[multiplex]

i believe its 14

[GintsK]

What engine, what injectors, what flyback type, what required fuel?

[multiplex]

3.2L inline 6, 24 valve head
65lbs injectors
43psi fuel pressure
flyback board
req fuel is 6.5ms

[rob@vems.co.uk]

3.2L inline 6, 24 valve head
65lbs injectors
43psi fuel pressure
flyback board
req fuel is 6.5ms

I think you need to use a 30V transient suppression diode to improve your injector closing times.  If you're using LowZ injectors then you need to use balast resistors (I suggest 6R8 50W) and to turn PWMing off.

Then you would benefit from looking at the opening values for the injectors.

Make sure that you are firing sequentially, and that you're injecting onto closed valves (match the fuel channels to the ignition channels)

Once you've sorted that you can get better resolution by halving the req fuel and doubling the values in the VE table (there's a scale table function in the VE table window) what this means is that you'll have VEs around 22 in your idle area, so you'll be able to set the value to 21.  But with better injector control you'll find that you have much more room for tuning adjustments.

[GintsK]

flyback board

That is cause!

As alternative for Robs "official" suggestion you can try my solution:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FGintsK%2FFlybackForLowZ

[MWfire]

or betther but complicated solution
http://www.vems.hu/wiki/index.php?page=MembersPage%2FDamirMuha%2FLowZinjectorsFlyback

[multiplex]

thanks guys.. that was what i was worried about..

this is were it gets complicated becuase I have the race logic traction control box inbetween the injectors and VEMS. this requires me to keep high imp injectors, and also makes the race logic box take the grunt of the flyback.

race logic box actually does control the injector better than VEMS alone, but its not as good as peak and hold, etc.

when will vems have traction control?

is there any talk of what will be available in v4?

I think for now i'm stuck

[rob@vems.co.uk]

You're not stuck because you're using HighZ injectors, so ignore the flyback talk and concentrate on the areas I suggested which were:

Then you would benefit from looking at the opening values for the injectors.

Make sure that you are firing sequentially, and that you're injecting onto closed valves (match the fuel channels to the ignition channels)

Once you've sorted that you can get better resolution by halving the req fuel and doubling the values in the VE table (there's a scale table function in the VE table window) what this means is that you'll have VEs around 22 in your idle area, so you'll be able to set the value to 21.  But with better injector control you'll find that you have much more room for tuning adjustments.

[multiplex]

thanks rob. i'll confirm my injection sequence - but i'm pretty sure i am firing into a closed valve.  I am currently running sequential

i thought about scaling, but won't that limit me on the top end? 

[rob@vems.co.uk]

What numbers are you getting on the top end, most fuelling tables are fairly flat.
Dont forget that the lambda table scales the fueling
VE(rpm, kpa) / Lambda(rpm, kpa)
So you can get more PW by lowering the lambda value.

Rob