fine adjustment on VW 1.8t 20v mk4

[rossi46numberone]

Hi everybody,

The car is running, and I have made my first meter on road !!
The engine idling like a charm ,and acceleration at mid-load seems good .
Now it’ s time for me to make fine adjustement….
My first question is why can’t I lean the idle air/fuel ratio lower than 12.25 ?
On my VE fuel table the values are near to zero,an exemple :
When idling,at +/- 900 rpm,the table value cell is « 2 » and mid-load about « 45 ».
And when I look on table from other guy,this values are much more high than mine
Where did I make a mistake ??
Can anybody help on the acceleration and cold engine enrichment % table ?

Thanks…..

[mattias]

Please publish a zip file with .vemscfg or .vemslog.

Are you running Speed-Density fuel algorithm?

[rossi46numberone]

My table use boost pressure /rpm...

Michele.

[ranz]

My table use boost pressure /rpm...

Michele.

No, under Base setup select Engine setup. What is the number on req fuel field? and VE table control strategy is what?

[rossi46numberone]

fix the problem 
it was the injectors trim value ,set to 100%.
decrease it to 75 % and my table look pretty good to do some fine adjustement!!!
At the same time the EGO correction issue solved and correction turn now around 97-99% at idle....
My req fuel is set to 5 ,Dwell :2.75.
Have tried the car on road pushing to 140 kpa and the car run fine!
Now I'm on the right way,thanks a lot guys for your precious advice and suggestion .

See you on next step:exhaust gaz temp and barometric correction.
 

[ranz]

I have also injector trim @ 100%, req fuel is 7,8 and VE table is @idle around 80.
So something else is right now richening a lot, because your req fuel should be something like 6,8 (you had 440cc injectors?).
The best thing is to post us the config file and we can help you a lot better.

[Jamo]

fix the problem 
it was the injectors trim value ,set to 100%.
decrease it to 75 % and my table look pretty good to do some fine adjustement!!!
At the same time the EGO correction issue solved and correction turn now around 97-99% at idle....
My req fuel is set to 5 ,Dwell :2.75.
Have tried the car on road pushing to 140 kpa and the car run fine!
Now I'm on the right way,thanks a lot guys for your precious advice and suggestion .

See you on next step:exhaust gaz temp and barometric correction.
 

I would say thats a band aid fix that's not addressing the real problem. You shouldn't have to touch the injector trims at all, it all indicates that your req_fuel is too high.  Try putting the injector trims back to 100% and increasing req_fuel value by 25%

[rossi46numberone]

ok,here is my config link file:
   http://www.box.net/shared/vc3vxe3yvb
thanks....

[rossi46numberone]

Yes I run 440 cc injectors@3 bar ,with 3.5 bar  they probably give +/- 500 cc.

[Sprocket]

I get rquired fuel at 6.2.

440cc injectors compensated for 3.5bar gives me 475cc, not 500cc.







EGO Correction step size is abnormally huge at 30%, should be at least 1% and no more than 5% in most cases.

Unless you are using ITB's with a turbo, MAP/RPM Correction table should all be set to zero.

[rossi46numberone]

What do you mean when you say ITB's?
Thanks for analysing my confiq and for these remark.
I'll try modiying this place et give you a feedback asap....

Michele.

[rossi46numberone]

What is the purpose EGO Correction step size?.

[rob@vems.co.uk]

What do you mean when you say ITB's?

Independent Throttle Bodies

[Sprocket]

ITB - Individual Throttle Bodies - One throttle body for each cylinder - 4 cylinder engine, 4 throttle bodies.

EGO Step size is the percentage of the active VE value, per step of EGO correction. Basicaly, with a step size of 30% any EGO correction with cause a change in fueling of 30% meaning huge swings in fueling. Look at it this way, if your VE table is out meaning there is an error in fueling of 10%, any EGO correction will result in an actual change of 30%, putting the fueling 20% beyond where it really needs to be.

Setting EGO step size to 1% as is suggested in the F1 dialogs means that EGO correction will only change in steps of 1% requiring 10 steps to get to the desired 10% correction, where as with 30% step size, 1 step would result in 30% change in fueling. 30% is just so wrong.

[Sprocket]

Actually I have just reallised. MAP/ RPM correction table should all be 100%. Everything for fueling is biased around 100% so 100% MAP/RPM correction is actually zero correction with 75% being subrtactive correction of 25% and 125% being an addative correction of 25%

This also stands for the injector trim you have set to 75%. This is not strictly correct, and they should all be set to 100% therefor, an actual injector trim of zero. Don't mess with settings that do not need correcting. while you may have achieved the result you are looking for, its not actually correcting the initial problem.