accleration enrichment on at idle

[Seight-v8]

hello all,

been for a Mot today after nearly 2 years of having my car off the road, and stuck in the garage.

Its not perfectly setup I know, but is getting there slowly, mainly to my lack of knowledge.

I noticed yesterday on my logs that I have 3-4ms of acceleration enrichment constantly showing at idle.

I've changed a few acceleration settings but cant seem to stop it happening.

I'm running latest vemstune with V1.2.13 for dual lambdas.

Any point me in a direction to help out.

cheers

scott

[lezsi]

I've only experience with 1.2.11 but it seems OK with accel enrichments.
Are you sure you're using sane dTPS values for Acc. dTPS/dMAP enrichment table?

Mine usually looks like:
dTPS        Enrichment
2              12%
15            30%
30            40%
60            50%

[Seight-v8]

I've tried changing some settings here but nothing makes any difference that I can see.

Although these settings are my current ones, they work when driving and flooring the accelerator, as my last ones caused misfires and bogging.

dTPS        Enrichment
5              30%
12            65%
30            78%
54            100%

But if the accelerator is not been pressed I don't think these should give my acceleration enrichment at idle, must be some other settings I am not seeing.

The engine idles quiet good even thought the AE is on at idle, but I think its best not to have it at all, during idle.

cheers

scott

[Erikk]

If you upload a .vemslog on the problem, then someone can have a look at it.

[Seight-v8]

ok this log was my run back from the MOT station on sunday, I also think I have added to much accerlation enrichment when the throttle is pressed as the lambda readings are going to 1.8 now, but at least the car doesn't bog down & misfire, so more work needed here.

But you should see every time the throttle goes to zero that there is about 4.0ms of acceleration enrichment showing, and this is what I cannot stop.

http://www.vems.hu/files/Scott_Richmond/

Otherwise car idles ok, which is weird.

cheers

scott

[gunni]

Looking at your log I don´t see Accel enrichment maintaining any enrichment when TPS is closed.
Also are you comparing Lambda to the exact same place as when you open the throttle back up?
If so then you need to take into an account at least 1sec delay at idle/low speed running to match up lambda to engine operation.
And sometimes it´s alot more then that.

Try it by logging and reviewing driving at steady state and then shutting the throttle, compare the time when it goes fully lean and when the injection was turned off. You can account that as most of your lag time for the lambda sensor, the reading circuit and the gases getting from the engine to the sensor.

I do think you have a bit to much accel enrichment though as you can see the mixture goes to 0.8 moments after putting your foot down.

[Seight-v8]

been out in my car friday, and i seem to have major problems with the acceleration enrichment, car jerks violenty when th pedal is pressed fairly quickly and it take a fews seconds to get back to normal, its like a major misfire at speed, and isnt funny.

Been trying a few accleration enrichment changes, and i cant seem to get it any better.

I still think acceleration enrichment is on at idle, as the log pic shows this and also the live vemsgauge while idleing, unless its a firmware problem.

If i disable it or change the settings to zero, the engine just nearly dies.....so i just done know where the problem is coming from.

I've attached an uploaded pic of the log with acceleration enrichment included, it shows 2.9ms at idle and this wont go away.



cheers

scott

[mattias]

I don't have the tuning laptop handy, I assume you also uploaded a vemslog to show this and not just a screenshot?

You should bring up the "calc" group/screen that shows how the pulsewidth to the injectors is calculated, there you can see all that affects the calculation and to what extent. Or just basically bring up a "calc gauge" to show the pulsewidth. Whatever.

[gunni]

I checked the previous log, there was no residual accel enrichment at all.

I´d be happy to look at the current log. Also remember that the data coming from the ecu isn´t EVERY channel you can log.
But Vemstune calculates somethings itself and then represents it. Clearly it saves on data transfer but isn´t the perfect solution at the same time.

That accel enrichment shouldn´t be possible with 0 dTPS/Dtime. give me a log and I´ll run it on my bench.

[Seight-v8]

ok so today i've done a log via my laptop with no accelerator pedal used, from cold to warm at 85degc.

I've looked at the "calc" screen and it shows acceleration enrichment on all the time, about 3-4ms.

I've uploaded this log to the file area, dated 09-06-13.

http://www.vems.hu/filethingie.php?action=list&subdir=Scott_Richmond

I did check a log from V1.1.99 froma while back, and this shows no enrichment on idle, and i have not changed any settings other than the ones that come with new firmware releases.....

Maybe a firmware bug in V1.2.13.

See what you think.

thanks for the help

scott

[gunni]

I´m looking at the log and I see zero movement on the Accel Enrichment at all.

Vemstune - 1.5.7 (2013.04.08) - http://www.vems.hu/download/VemsTune/dev/VemsTune-sequencer-2013-04-08.exe

Can you verify that this is an actual calculation by the ecu and not vemstune? In Injector calibration you can see VE Pulse width and ECU puls width. Sometimes they differ due to the ecu having upto date values that Vemstune does not.

[Seight-v8]

gunni,

yep its all gone using that version of vemstune, so looks like that was the problem, been worried about that for a few days.

Thanks for your help.

scott