Help with DBW/Idle Control Configuration

Hey all,

Been working on my first calibration with M1 Tune and my first time setting up a DBW application.

Details: 1986 Supra, 2jzgte VVTI, Bosch 68mm DBW, Lexus SC430 Pedal, PHR Hall Effect Ref/Sync, GTR Hitachi Coils

I went through the Pedal setup and Servo Setup worksheets and was able to get items to calibrate and it appears everything is tracking well and diagnostically the setup appears to have no issues.

When starting the car, idle is fair and no issues present. As soon as throttle is applied via pedal (small amount or moderate) the engine speed instantly starts to climb north 3k and lands in 4k area and does not return unless the engine is turned off. During this event the Pedal shows 0% translation and the Servo shows around 7.8%. Idle aim is set at 10%

I'm a little lost as to what could be causing this issue. Any chance someone could look at my settings and weigh in? If someone can fix the issue or is willing to help solve my DBW woes I would be happy to compensate for time. I have a show coming up in few weeks and so far haven't even been able to drive the car lol.

Cal: [url=https://drive.google.com/file/d/1_t7TyDCBCGd-4kDMmmo_S_NvCkfrf8rh/view?usp=sharing]https://drive.google.com/file/d/1_t7TyDCBCGd-4kDMmmo_S_NvCkfrf8rh/view?usp=sharing

Log File (End of Data Set, but similar events before, last event is fresh calibration of both units):

[url=https://drive.google.com/file/d/1h4V3dB9-mSNfOptZzT7p_a1eZr4LkN07/view?usp=sharing]https://drive.google.com/file/d/1h4V3dB9-mSNfOptZzT7p_a1eZr4LkN07/view?usp=sharing

Thanks in advance!

First, I suggest you change a few parameters:

(on Engine Systems->Idle Aim tab, Idle Setup Parameters):

Idle Activate Throttle Pedal Threshold -- lower from 1.5% to either 0% (as recommended by the help), or very low 0.5% or less.

Idle Activate Throttle Pedal Hystersis - change to 0.1%

Idle Activate Engine Speed Margin (this value can be made larger if you have throttle hangs) -- I think it will be OK when everything is right, but for now, this is why ignition is not retarding even though you have 0% throttle pedal.

After this I would work on tuning your Idle Mass Flow Feed Forward Main table (Engine Systems->Idle Actuator; Idle Mass Flow pane). Because your target idle is initially about 1600 RPM (after your blip), and the coolant temp is about 100F, The table holds the throttle at about 6%, and your engine runs at 3000 RPM with that much throttle open. Make the number in the 1600 column be about 50% or so at 104F and I bet that will help the engine slow down.

To tune this table, just temporarily change the Idle Aim Main to target one RPM at all temps, and adjust the values to match the "Idle Mass Flow Feed Forward" that is resulting from the Integral and Proportional gains. Do this as the engine warms up. Start with the 1600 RPM, so you can "bound" the values you will need for the table.

I find it helpful to turn on a bit of Idle Mass Flow Proportional Gain while dialing this in as it will get the throtte homing in on the necessary value quicker.

Hi,

I have pretty much made the same changes that David has suggested in the previous post with the attached file. As David said, the main area to work on will be the Idle Mass Flow Feed Forward table, I think that the numbers are too high in this table as well, I have also added an extra column at 1700 rpm with low numbers to assist in dragging the throttle closed and transitioning into idle quicker.

Thanks gentleman! I'll really appreciate the help and will report back after trying.

Thank you Dave and Stephan for coming in big! It behaves much better now and seems to be hitting the target much better. I also changed my Idle Aim to 4% from my previous 10%.

I will continue to work this table and hopefully learn how to properly dial it in. I've reread Dave's post a few times and plan to try to "band" it as suggested. I did take another log incase either of you would be willing to look.

Thanks again guys! Much appreciated, this is an area I have yet to dabble in and the learning curve is steep lol.

https://drive.google.com/file/d/1RJmV-cU5ULy11zbQJk8tMGwdvb9Rm5Lq/view?usp=sharing

https://drive.google.com/file/d/1-17vv-pTwuMTeOBRO0rRcunnqsS3fJOX/view?usp=sharing

Try this file to deal with the hanging engine speed.

I will give it a spin.

While I have your ear. Do you happen to know if the AEM 30-2012 Fluid Temp sensors have a Calibration chart for the M1? I am trying to use them for oil and coolant Temps and can't seem to get a good realistic read. I suspect it's because they are 2.2k pickup and the M series uses 1k.

It's just a bummer because the harness is fully terminated and hacking it apart to change the connector will break my heart. Ha ha

Thanks again for the help with the DBW/Idle Control cal. It is quite perplexing but making more sense.

Try this as a table.

Temp

Volts

-40

4.938

-20

4.908

-10

4.875

0

4.823

10

4.742

20

4.624

30

4.455

40

4.229

50

3.948

60

3.622

70

3.255

80

2.810

90

2.443

100

2.067

110

1.728

120

1.432

130

1.178

140

0.969

150

0.794

Temp

Volts

-40

4.938

-20

4.908

-10

4.875

0

4.823

10

4.742

20

4.624

30

4.455

40

4.229

50

3.948

60

3.622

70

3.255

80

2.810

90

2.443

100

2.067

110

1.728

120

1.432

130

1.178

140

0.969

150

0.794

Thanks for the continued help Stephen! I will try the Package and this calibration and report back soon!

Hey Stephen,

I loaded the file and was planning on trying you calibration table above. Sorry for ignorance, but how to you set the breakpoints for the coolant temp sensor in the define axis menu? It will only allow me to change the voltage but I can't seem to manipulate the temp breakpoints to make them coincide with the supplied table.

I have included the link to the most recent Package with the changes you had recommended above.

Thank you again for you time sir.

https://drive.google.com/file/d/1y6zkzswmxBAD4fo00Nz8yK4jy6oush7L/view?usp=sharing

Click on the the translation table to highlight it, and then either press "a" on the keyboard or right click and select "Setup Axis" from the popup menu.

Hey Stephan,

Tried the file. Wasn't able to run it but did note some variations with those higher values in the 1700RPM column. The "hang" moved to almost 2k as I recall but did seem to consistently come down faster. I am planning a drive tomorrow to get some logs with load.

I was able to get the table loaded but unfortunately it is still reading wildly inaccurate at most temps. I guess I will order up some RaceGrade DTM 1/8" and just repin... I tried a MoTec generated table as well but that also wasn't very effective. I ended up trying to rough cal it with a temp gun but it just won't do long term.

I included my Package file and logs (the end is the majority of the DBW throttle translation/idle control).

Thanks again for taking the time, its much appreciated.

Trevor

https://drive.google.com/file/d/1Tm0JWLAs5an3x1D455xpXW00uTl1cSf8/view?usp=sharing

https://drive.google.com/file/d/1wVl1tPQnF0UptC4--JuvUsBkpWo39SD-/view?usp=sharing

https://drive.google.com/file/d/1hyhAYob9bJ8-I46AllfvVtYFviqRaMEa/view?usp=sharing