Audi RS2

[AVP]

can you explain to me why it is going to retard a lot for ignition based timing?

[AVP]

in the acceleration amount values, is it the higher the number = the more fuel is added on pressing the accelerator pedal?

[AVP]

im going to try to recalibrate the TPS as well today and if idle does not respond i may go for the IAC/diode solution and play around with those settings.

i have noticed also that when stationary and on idle, if i press the accelerator and release it, that is also when the small dip in revs as well as 'missfire' like feeling is there. On datalogging i think it gets too lean on that time.I get lamda values of 1.5 something. So which way should i change the acceleration enrichment table to compensate?

here are some more tables:

here on the accel.enrichment the accel amoun (0) was 0.7 and i have used 0.3 but havent tried it yet.

[[email protected]]

can you explain to me why it is going to retard a lot for ignition based timing?

If the current RPM is higher than target then the ignition based idle will retard in order to reduce the engine speed.

in the acceleration amount values, is it the higher the number = the more fuel is added on pressing the accelerator pedal?

Acceleration Bins is how quickly the pedal is pressed, and the Acceleration Amount is the length of time added to the injector's PW to add more fuel.
The recommended Acceleration Bins values are:

• (dv/dt) 1
[1](dv/dt) 5
[2](dv/dt) 20   
[3](dv/dt) 40

im going to try to recalibrate the TPS as well today and if idle does not respond i may go for the IAC/diode solution and play around with those settings.

TPS calibration is never a bad thing to do, although unless the TPS is over 2% (look at: Extras->Idle Settings and you'll see that TPS value for idle threshold(%) is set to 2)
calibrating it will not have any effect.  It should be 0% when the throttle is resting on the throttle stop.

[AVP]

right,
after calibration tps off was : 0 and TPS WOT was 255. So i entered those values on the basic settings screen.

today i tried the idle settings of the diode,but again i could not get the damn idle to settle @ 900 or 800rpm. Also when i turned the advance based idle off, it still didnt do much. On my spark table on idle i get the 2nd bin lighting up where i have 30.75 advance angle and that makes the idle with around 20deg. of advance as it sits between 700 and 1200rpm. However when i reduce that value to 18.75 for example i do get the idle to sit lower, BUT i get higher EGT on that setting.

Now how can i actually get the idle to listen to the commands i set???

I also made the change on the acceleration bins,

tell me something: is the highest the number, the faster the acceleration pedal responce? is that how it goes?

Also, is there any correspondence among the 4 bins and 4 accel.amounts? would the value of the 1st bin correspond to the value of the 1st accel.amount?

I managed anyway to get it a bit better on soft pedal depression,but on gear change,it still bumps no matter what numbers i have tried,

i also noticed that with the pedal depression on idle and stationary, while making those changes, it seems that EGTs are getting quite lower, which is not something that is happening with the motronic on similar circomstances!

[[email protected]]

Those numbers sound incorrect to me, have a read of this:
http://195.159.109.134/vemsuk/forum/index.php/topic,600.0.html

Is the throttle properly closed, or is it open a bit?  If its open, with the best will in the world you're not going to a low idle, if there is an idle adjustment screw you should:
Ensure that the ICV is closed.
Turn off the ignition based idle.
Reduce the idle speed using the adjustment screw.

This will then make cold idling difficult as the engine will not rev high enough - so you'd then need to get the ICV working properly.

Until you have the TPS spot-on you'll not be able to get the acceleration enrichment even close.
When you map the car you dont want acceleration enrichment on anyway.

Tuning is a very complex subject because of the huge number of variables that are in play, don't underestimate the amount of learning and experimenting that you'll need to do.

[AVP]

the issue here is the fact that the throttle body has not been tampered with or altered in any way from factory. So to have the screw altered should not be the solution, since others that have been using VEMS on 20V 5cylinder turbo engines, never had to go through that procedure themselves to achieve good idle.

When the throttle is completelly closed, it clicks.That is how motronic understands and receives that information to control idle.However on VAGCOM with closed throttle you always get a reading of 8 deg. angle for some reason, without that interfereing with how idle is managed by motronic.

Initially, mark had used numbers 23 and 240 for TPS. Calibration gave me 0 and 255. So why would those 2 numbers from calibrations be wrong?

on idle and on main screen the TPS gauge shows 0. ISnt that what it should show?


here is also a config file i have.im not sure if this was done when i did the calibration:

 MegaTune-generated Linear Throttle Calibration
; Written on 2009-05-15T18:57:42+01:00
;
;   Low ADC = 0    High ADC = 255
;
THROTTLEFACTOR:
         ; ADC
   DB     0T   ;   0
   DB     0T   ;   1
   DB     0T   ;   2
   DB     1T   ;   3
   DB     1T   ;   4
   DB     1T   ;   5
   DB     2T   ;   6
   DB     2T   ;   7
   DB     3T   ;   8
   DB     3T   ;   9
   DB     3T   ;  10
   DB     4T   ;  11
   DB     4T   ;  12
   DB     5T   ;  13
   DB     5T   ;  14
   DB     5T   ;  15
   DB     6T   ;  16
   DB     6T   ;  17
   DB     7T   ;  18
   DB     7T   ;  19
   DB     7T   ;  20
   DB     8T   ;  21
   DB     8T   ;  22
   DB     9T   ;  23
   DB     9T   ;  24
   DB     9T   ;  25
   DB    10T   ;  26
   DB    10T   ;  27
   DB    10T   ;  28
   DB    11T   ;  29
   DB    11T   ;  30
   DB    12T   ;  31
   DB    12T   ;  32
   DB    12T   ;  33
   DB    13T   ;  34
   DB    13T   ;  35
   DB    14T   ;  36
   DB    14T   ;  37
   DB    14T   ;  38
   DB    15T   ;  39
   DB    15T   ;  40
   DB    16T   ;  41
   DB    16T   ;  42
   DB    16T   ;  43
   DB    17T   ;  44
   DB    17T   ;  45
   DB    18T   ;  46
   DB    18T   ;  47
   DB    18T   ;  48
   DB    19T   ;  49
   DB    19T   ;  50
   DB    20T   ;  51
   DB    20T   ;  52
   DB    20T   ;  53
   DB    21T   ;  54
   DB    21T   ;  55
   DB    21T   ;  56
   DB    22T   ;  57
   DB    22T   ;  58
   DB    23T   ;  59
   DB    23T   ;  60
   DB    23T   ;  61
   DB    24T   ;  62
   DB    24T   ;  63
   DB    25T   ;  64
   DB    25T   ;  65
   DB    25T   ;  66
   DB    26T   ;  67
   DB    26T   ;  68
   DB    27T   ;  69
   DB    27T   ;  70
   DB    27T   ;  71
   DB    28T   ;  72
   DB    28T   ;  73
   DB    29T   ;  74
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   DB    30T   ;  77
   DB    30T   ;  78
   DB    30T   ;  79
   DB    31T   ;  80
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   DB    32T   ;  83
   DB    32T   ;  84
   DB    33T   ;  85
   DB    33T   ;  86
   DB    34T   ;  87
   DB    34T   ;  88
   DB    34T   ;  89
   DB    35T   ;  90
   DB    35T   ;  91
   DB    36T   ;  92
   DB    36T   ;  93
   DB    36T   ;  94
   DB    37T   ;  95
   DB    37T   ;  96
   DB    38T   ;  97
   DB    38T   ;  98
   DB    38T   ;  99
   DB    39T   ; 100
   DB    39T   ; 101
   DB    40T   ; 102
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   DB    41T   ; 105
   DB    41T   ; 106
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   DB    43T   ; 110
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   DB    98T   ; 250
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   DB    98T   ; 252
   DB    99T   ; 253
   DB    99T   ; 254
   DB   100T   ; 255

[[email protected]]

I see what you are saying - if the TPS calibration showed the throttle as being 8% open then the Idle control will never come in, because the the threshold is set to 2% (as I wrote in a previous post).
The calibration wizard never seems to work properly - that thread explains how I calibrate a TPS.
You want the VEMS to read 0% when the throttle pedal is up, and 100% when the throttle pedal is down.

[AVP]

Thanks for that Rob.

i fixed that now!

under tuning/acceleration dotrate/% you get the scale you need to tune for accel.enrichment.

i seemed to be able to fix accel.enrichment faster through there,but all changes i made there, were not impleneted in the settings window after that. Should they be there,or is tuning something you see real time and once you are happy with what you have,you go back to the window and put the new values in?

vasilis

[[email protected]]

Don't forget to Burn to ECU after your changes.

[AVP]

good think you mentioned that. it seems that when i do changes, ECU responds withough me having to burn to ecu. I do press the button,but i can see the responce from the engine even before i do that.

so is the burn to ecu always needed?

[AVP]

also, quick question:

i realise what PID means,

can someone tell me what the integral increase/decrease means, as well as the deadband for integral and IAC? (rpm)


thanks

[[email protected]]

The best explaination I've seen is this:
http://en.wikipedia.org/wiki/PID_controller

[AVP]

after a little more time playing around i noticed that when car is warm and idle is fully controlled by ignition timing (IAC ref table 71C = 0) as i said before the EGTs are higher than what i would like them to be.

even after a short drive, the car goes to neutral or stops and EGTs are all the way up to 580C to 600C when really they should be around 100 degrees less. On motronic i would only see for a short time 550 max after a long drive,so i think i should dig into the IAC controlled idle more although ignition based idle seems easy and steady.

I have noticed that the more i use the IAC on warm engine, the more tuning it needs BUT the lower the EGTs fall.

Finally, since motronic always has about 8deg of TB open when the accel pedal is not pressed, i thought of trying something else. If i increase the amount the IAC is contributing to idle through the ref table, and give a bit of TB angle into it, the idle seems to rise a bit.AND EGTs fall.

there is a pattern there and i will look into it more...

[[email protected]]

Make sure that the TPS is right for the VEMS, while its a good idea to compare the two systems, they will have different readings and different features.