Newbie VE mapping

[206Rob]

Hi All,

I am completly new to injection mapping.. Did already many readings here, and starting to understand things. Have the following:
making a turbo conversion on my 206. Completed the mechanical part. Fitted the vems, came from DP with standard engine mapping.

I left ingition table as it was, and started building the VE map, as it was empty. Now the car is running (very bad). I have it now up to the point that it runs nice with very little throttle till approx 4000 rpm then the turbo starts kicking in. When TPS is above 50% the car stops very abrubt. Which telling me that i am to lean.

I am trying to reach lamda target, but half off the time i get no lambda readings?? Is it possible that when i am that far off off i a outside the lamda range so it doenst count? Lambda readings are a lot on zero.. Which would mean that i am to rich. Cutting fuel gets lamda values up to range, but then the car wont drive, and make no rpm at min. TPS?

As i am a complete newbie in this, i would like to know how to get a "feel" vor the valeus i have to put in. Or am i overlooking something else completly

(when the car is driveable ill let it finetune it on the dyno at DP, but i want to unserstand the if an what.. about FI)

[GintsK]

It is not best idea to start with turbo engine... 

First start with required fuel calculation (hit F1 for instructions when accordant Vemstune window is active) . Then fill VE map with something like 50...70 at idle region and closer to 100 at higher loads and rpms. and you will be in ball park. Somewhere before final VE mapping try to find injector dead time values because wrong values disturbs VE map and all internal calculations becomes imprecise.

Yes you can get good lamda readings in 0.7...1.25. Below 0.7 it is common to see 1.25 again...

Gints

[206Rob]

Ok thanks, i'll try getting there.

Do i understand correctly, that if i am way far off, lambda flicks over?

Rob.

[GintsK]

Yes.

[206Rob]

Thanks for the treply

one more question...

I remapped, geuss should i have with constant throttle lambda near target, and go thru all rpms at given engine load? And slowly remap till it is ok.

When i am near, i am at valeus below 30 in the table. lambda is ok, but accelaration is impossible, the engine doent like it. Auto tune however says i am spot on? does it use same lambda target / algoritmes to calculate valeus? And is it possible when i am far off that the calculation is screwed up also?

Geuss i am am far off and tried 50 till 100, car drives much better, but lamda is nowhere to see 0 readings all the time?

[GintsK]

Seems your lambda readings is way off? Right?
Are you sure about ECU calibration values? Did you performed free air calibration before O2 sensor install?
What you knew about flyback TVS diode? Is it installed?
 

[206Rob]

Yes, lamda is fluctating, many times 0, then rapidly up to 1.3, and rapidly back to zero. , have to mention though with no throttle on engine brake is fairly constant in the .8 - .9 range.

Yes calibration is ok, double checked it.
Flyback diode? sorry no idea what it is.

[206Rob]

Ah.. BTW think it is already in de vewms case, prepared by DP

[GintsK]

Yes, lamda is fluctating, many times 0, then rapidly up to 1.3, and rapidly back to zero. , have to mention though with no throttle on engine brake is fairly constant in the .8 - .9 range.

I saw something like this with dead sensors. It can be caused from overrich mixture.
Are all WBO2 PID values are default? (see dropdown menu at bottom of accordant window)

Gints

[206Rob]

yes, pid valeus are default. Tomorrow i'll go testing sensors en see what i can measure find.

If i cant find it ill drive by DP bedore the weekend and let them check my logs, maybe i am missing somthing stupid  as this is most likely the case in most issues..

Another question, you might help me further with,  or should i post this in  a other section?
At 120 kPA the engine cuts looks like, is this boost controlsettings possibly? I have boost valve off below this pressure, set at 120 KPA, but havent  got a boost mapping yet, or set any ref's. But also have boost PID set at enabled.

was thinking with more throttle aplied boost kicks in rapidly, and if somthing cuts the engine at higher pressures, it might infere lambda? or am i thinking way out of the box right now?

[andreNL]

Going from 0 to 1.29 means injectors open to long (0) then be closed by correction (1.29)
This can be flyback not working properly.
But first check req_fuel
Disable engine cut at deceleration
Dont touch boost cut till fuel delivery works fine
Disable acceleration enrichments
Make sure engine is warmed up well
Dont use to lean or rich in lambda table

If you are at VE 30 and you accelerate kpa changes upwards, go rich in lambda table like 0.86 at higher kpa value .
Dont change VE, if you need beter resolution divide req_fuel by 2
And double VE

[206Rob]

Ok, thanks for all info. ill check and give it a try

Tonight i saw a short trigger error red in top off vems occured only once or twice... I replaced flywheel sensor, from my spare engine, and made a short run, already was getting late . But looked much better! now evrything react s different. I'll start to redo my VE map tomorrow. As now the valeus in the log make sense, and lamda is more constant

could this be the error? Strange as i never had problems with the original comp. Looks now i finally have found somthing..

[boostd audi]

lambda actual / lambda target = a multiplyer, then multiply that to the value on your ve table at the exact rpm and map load site where you took the lambda's  calculation. 

[mattias]

lambda actual / lambda target = a multiplyer, then multiply that to the value on your ve table at the exact rpm and map load site where you took the lambda's  calculation. 

VemsTune already does that calculation for you, just plot "calc -> ego corrected ve" on top of "basics -> ve current", and get immediate feedback on how far off you are.

[206Rob]

Thanks all, trigger error caused the problems somehow.

Now solved it and car runs like a jet engine.

Have to sort out idle now and a 2100 rpm dip.