Audi RS2

[AVP]

Finally, did the timing test.

ignition based timing disabled, i had good idle with 14deg. Strobe light showed 13.7deg.

I didnt change anything.left everything as it was. I think it is close enough

[AVP]

recently i have been getting a bit of oscillating idle and it is not related to the wideband,but it is related on the IAC unfortunatelly.

So far it used to work quite efficiently.However now when i test it on warm engine and with EGO off, i have the idle barely oscilating, very small amount, of about 50rpm however the lamda values fluctuate from 0.95 to 1.05 lamda and that is why the oscillation is there.

I tried a few different settings here and there,and it seems that ego correction cannot compensate for that oscillation,and the oscillation is related to the IAC,cause once i turn that off, the lamda is stable.

I use as IAC pwm speed : 2
and steps of 100. I tried various different values on that,and it didnt make much of a difference.

if i increase the pwm speed the IAC dies when speed is above 6 or 7.

On idle pwm banks i have about 15 and that is the highest i can use to keep the idle from plummiting when the AC is turned on.
My spark @ idle is 16-17deg and when i reduced it to 12 it seemed to be more stable.

does anyone know why the IAC is causing that amount of oscillation on the idle?

Also if i were to completelly take off the IAC, what would the best settings be to have as lowest idle as possible? cause so far i can only get it to 1050rpm.

[GintsK]

Two things. Only iac speed normaly usable is 0.
And - have you diode instaled parallel to IAC valve?

Gints

[AVP]

diode is fitted there yes.
i have never tried 0. What would this mean? only other settings i have seen were never 0.

thanks, i will give that a go as well

[GintsK]

0 gives smother PWM signal as possible. all others have interrupts for some reason. 0 is same as 64 AFAIR.

[AVP]

havent tried it yet.will report back

[AVP]

Well.,
indeed the pwm=0 makes things more easy.

i used 14.50deg spark on idle and 110 steps to move.

Idle now is much more steady,around 900-950rpm and drops very little with AC on.

Also my idle pwm @ 71.1C is 17 for now. I have noticed that using the ignition based timing only on warm up and slowly give the IAC more speed as the engine reaches it's correct temperature,has a good effect on cold starts and everything.

SO ill keep it like that for now and see how it goes.

[gunni]

Post up your screenshots of the idle control related windows.

[AVP]

Here you go:

[AVP]

another test done today all looks good!

i got the lcd from VEMS today and im waiting for a custom made aluminium plate to fit on the main dash.I tested it and it looks very nice!

[peter_jensen]

Hi vasilis

Try this

Idle settings:

Speed/pwm= 0
Max steps to extend = 255
Tps value for idle threshold = 2
Idle settings advance

P= 40
I = 2
D= 21
Integral decrease limit = 12
Integral increase limit  = 12

Idle control pwm table

15,5= 57
26,6= 51
37,7= 46
54,4= 42
71,1= 39

Position at –40= 40%
Position at 77= 100%


Regards
Peter jensen

[AVP]

peter,
thanks, i have tried the settings when you posted them on s2forum. they were no good on my rs2. idle was all over the place and very little control with AC.

with the settings set as they are, i have everything pretty much sorted. Also idle is very much depended on what spark you have on idle so it is not correct to always have the same settings.

also PID integral decreace limit should always be slightly smaller than increase as this tends to keep idle less frequent in dipping when the fan kicks in or in AC operation.

With i P of 40 idle on my car tends to oscilate after a disturbance.

[AVP]

the only thing that sounds more logical on those settings is the IAC pwm on cold and warm, however when i try to use those settings i get a big dip on the idle as soon as it cranks,although it may not stall.However when i have it the other way around, it seems much more stable

[AVP]

well turbosmart solenoid is installed with the configuration that i posted before.

results are fantastic!! boost is now much more precise, hits the rpm vs map table 100% and only drops a little on 3d and 2nd gear on high rpm which is normal for my small turbo(too much back pressure!!), so i think i will stick with this one.Its a winner!!

anyone that needs the settings i used let me know!

[gunni]

Post them up and your solenoid part number.