Stepper idle valve stop moving

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Suprazz
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Stepper idle valve stop moving

Post by Suprazz »

I have an issue where when I play with the idle valve position in open loop mode in the warmup position table. Sometime the idle position update and sometimes (most of the time) it doesnt do anything (the gauge in tunerstudio stays at the same value and doesnt go to the warmup value).

I need to restart the engine to see the effect. Any idea why?

I never understand why it always does that.
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Matt Cramer
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Re: Stepper idle valve stop moving

Post by Matt Cramer »

Can you also data log what's going on?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

tunerstudio just does nothing.

Example: The valve is set to 80 steps. I start the car, and the valve moves to 80 steps.

Then, I change the value in the table to 70. Sometimes the valve will move to 70, sometimes not. If I edit the number again, to 60, if the valve didnt move it wont move again.

It's very easy to recreate the issue on the bench.

I made a quick video: https://youtu.be/z_C_HhXmgSE
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Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

I'm sure I'm not the only with this issue. It's been there for a long time.
Best looking and most advanced CAN-bus gauge
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billr
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Re: Stepper idle valve stop moving

Post by billr »

Do you mean the issue of not wanting to post the requested MSL? Yes, we run into that all the time...
Matt Cramer
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Re: Stepper idle valve stop moving

Post by Matt Cramer »

Are you able to get an oscilloscope on the output? This will help see if the ECU isn't trying to move the valve, or if the ECU is trying but the valve is stuck.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

Hi,
No the valve is not stuck.

The ECU does nothing. If I go in test mode, the valve start to move.

The issue is related with the warmup mode only.

Thanks
Best looking and most advanced CAN-bus gauge
Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
Serial to Bluetooth or Serial to WiFi
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Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

And when I exit test mode, The valve goes to the right position.
Best looking and most advanced CAN-bus gauge
Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
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billr
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Re: Stepper idle valve stop moving

Post by billr »

I understand what you are saying about the step change not showing up in TS (or the IAC motor). I also noticed in the video that your CLT dash gauge is in deg. F, but the idle warmup table is in deg. C I wonder if that may be confusing things? When you make changes in the table in the 10-20C cells, it has little effect on the engine since it is at a a way-lower temp (11F = minus 12C?)

OK, I looked at the video again. Is it just the dash gauge that is labelled wrong? It seems the CLT is at 11C, not F. Again, a run log might help...
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

Hi,

I dont think the C vs F is not the issue. I can reproduce the issue whenever I want.

Once the valve moved to the position, we cannot update it directly in the idle warmup table. If I change the value there, the valve doesn't move.
Then I can go into test mode. Set the valve to a higher value. The valve will move immediately to the requested position when I press the button run to the position. And when I leave this window. The valve will move back to the right position.
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Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
Serial to Bluetooth or Serial to WiFi
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Re: Stepper idle valve stop moving

Post by jsmcortina »

I'm pretty sure I know what this is.
In stepper warmup mode, the code will only lookup a new position value if the coolant temperature has changed by a certain number of degrees. This originates from MS2/BG.

James
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billr
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Re: Stepper idle valve stop moving

Post by billr »

Ah, is this an MS2? I missed that. I guess this is yet another slight difference between the MS3 that I know and MS2... Sorry, if I confused the issue.
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Re: Stepper idle valve stop moving

Post by jsmcortina »

MS2 and MS3 are likely both the same (presently) as they both evolved from MS2/BG.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

same issue with ms3.
Best looking and most advanced CAN-bus gauge
Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
Serial to Bluetooth or Serial to WiFi
DIYAutotune Canadian, EFI Source and ECUMaster reseller!
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

Yes James, that make sense!
jsmcortina wrote:I'm pretty sure I know what this is.
In stepper warmup mode, the code will only lookup a new position value if the coolant temperature has changed by a certain number of degrees. This originates from MS2/BG.

James
Best looking and most advanced CAN-bus gauge
Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
Serial to Bluetooth or Serial to WiFi
DIYAutotune Canadian, EFI Source and ECUMaster reseller!
billr
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Joined: Sun May 15, 2011 11:41 am
Location: Walnut Creek, Calif. USA

Re: Stepper idle valve stop moving

Post by billr »

But, but... I'm pretty sure my MS3 does respond to changes in the open-loop idle steps. I'll have to check that out the next time I drive the beast.
Suprazz
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Re: Stepper idle valve stop moving

Post by Suprazz »

sometime yes, but not always. Try it
Best looking and most advanced CAN-bus gauge
Toyota Supra 7MGE, 7M-GTE and 1JZ-GTE Plug and play ECUs: http://www.perfecttuning.net
Serial to Bluetooth or Serial to WiFi
DIYAutotune Canadian, EFI Source and ECUMaster reseller!
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