MS3X 100% idle duty cycle - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

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Old 06-25-2014, 11:41 AM   #21
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Quote:
Originally Posted by Braineack View Post
1. the idle is just messed up. why, i dunno. A fully opened idle valve should shoot the idle to around 3000RPM. I don't think it's software related though.

2. messed up your wiring or settings.

3. tune your cam zero-point pot (should have been turned at least 3 full turns CW)
1: Yeah, I'm kind of at a loss on that one at this point.

2: I'll double check it.

3: I'll turn it 3 turns clockwise and see if that fixes it.
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Old 06-25-2014, 12:14 PM   #22
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The latest FW has an initial duty table for the idles valve setting. X-Axis is rpms and Y-Axis seems to be coolant temp. Values are idle valve duty. This is where your FW looks up your initial setting for the idle valve PWM when the TPS goes to 0%. Set that to the value that's usually needed at a certain temp to reach your target rpm for that temp.

Are you sure 511Hz is a good frequency for the idle valve? I believe I'm running 75Hz and that seems to work very well.
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Old 06-25-2014, 12:37 PM   #23
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Originally Posted by stefanst View Post
The latest FW has an initial duty table for the idles valve setting. X-Axis is rpms and Y-Axis seems to be coolant temp. Values are idle valve duty. This is where your FW looks up your initial setting for the idle valve PWM when the TPS goes to 0%. Set that to the value that's usually needed at a certain temp to reach your target rpm for that temp.

Are you sure 511Hz is a good frequency for the idle valve? I believe I'm running 75Hz and that seems to work very well.
This thread seems to say it's 500Hz. I'll definitely double check that idle table though.

https://www.miataturbo.net/megasquir...control-54877/


The main issue I'm still confused about though, is the fact that at different times it is taking different duty percentages to reach the same idle goal. That doesn't make sense.

Last edited by Schuyler; 06-25-2014 at 05:09 PM.
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Old 06-25-2014, 07:34 PM   #24
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Originally Posted by Braineack View Post
3. tune your cam zero-point pot (should have been turned at least 3 full turns CW)
Turned it (R11) 3 full turns CW, made no difference. Should I turn the pot on the main board 7 turns CW as I saw you recommend in another thread?

EDIT: 7 turns CW on the main board pot made the car not crank.

EDIT EDIT: Video of the issue -

Last edited by Schuyler; 06-25-2014 at 08:26 PM.
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Old 06-25-2014, 08:29 PM   #25
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take a composite log a see if youre actually losing the crank or cam signal...

logs provide awesome info.
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Old 06-25-2014, 08:34 PM   #26
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Quote:
Originally Posted by Braineack View Post
take a composite log a see if youre actually losing the crank or cam signal...

logs provide awesome info.
Will do, give me an hour or so and I'll be back at my car. idk if it tells you much or not, but here is a screenshot I'd posted of the issue in my build thread (thought i'd posted it here)

Log pic:
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MS3X 100% idle duty cycle-fcrobkm.png  
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Old 06-25-2014, 08:57 PM   #27
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You got sync issues!

A composite log may give you better info. It will tell you if the Cam or Crank sensor is the problem. Or maybe both...
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Old 06-25-2014, 09:18 PM   #28
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The signal I'm losing is the green line. Fiddling with the pots seems to have given me a few hundred extra rpm. I had reset the main board pots, but left the three added turns on the expansion r11. Which pot would have influenced this signal?

(No WiFi to post composite log)
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Old 06-26-2014, 12:16 AM   #29
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I've fixed it. I honestly just played with the pots on the expansion board, revving the car up every few turns until it worked. Now to figure out my idle and get rid of these WOT lean spots.
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Old 06-26-2014, 12:06 PM   #30
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Quote:
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I've fixed it. I honestly just played with the pots on the expansion board, revving the car up every few turns until it worked. Now to figure out my idle and get rid of these WOT lean spots.
Good Deal
Yes 511 Hz

Idle PWM % will very for the same RPM due to the mass of variables involved in idle, including Alt load, temp, and things beyond me. So hence the need for closed loop to alter the valve setting to maintain idle.

I prefer to "Use initial value table" rather than "last value"

Suggest you use CLT, not MAT for the idle speed set point from value table.
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Old 06-26-2014, 12:13 PM   #31
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Good Deal
Yes 511 Hz

Idle PWM % will very for the same RPM due to the mass of variables involved in idle, including Alt load, temp, and things beyond me. So hence the need for closed loop to alter the valve setting to maintain idle.

I prefer to "Use initial value table" rather than "last value"

Suggest you use CLT, not MAT for the idle speed set point from value table.
I'd been using use last value because the car can't seem to figure out what duty % it needs to use, and corrects itself when it bogs way down (usually requiring it to go to 100%) , and then idles alright. With "last value" on, it seems to remember this and hopefully behaves next time I come to a stop. Though after driving for 20 miles or so it seems to change values and want to stall when I come to a stop once again. Car wouldn't crank this morning, so I had to take another car to work. I will try to tackle whatever is causing it not to crank (i have an idea or two), and then try to do some work on the idle. I'm thinking I might need to open the idle screw some more? 100% should be a much higher rpm than 1000.
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Old 06-26-2014, 12:29 PM   #32
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why aren't you using the intial duties table?

ive said it like ten times now, 100% DC should be like 3000-4000RPM.
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Old 06-26-2014, 12:45 PM   #33
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Quote:
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why aren't you using the intial duties table?

ive said it like ten times now, 100% DC should be like 3000-4000RPM.
Will switch to initial duties table this evening and turn idle screw until 100% duty is 3000rpm or so.
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Old 06-26-2014, 12:57 PM   #34
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good luck getting the RPMs back to 800rpm until you figure out why the MS isn't commanding the valve correctly
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Old 06-26-2014, 01:14 PM   #35
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What would you suggest my next course of action be? Aside from changing diodes, I'm out of ideas to handle things on MS' side. 100% in idle valve test has me at like 975rpm.
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Old 06-26-2014, 01:41 PM   #36
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Quote:
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good luck getting the RPMs back to 800rpm until you figure out why the MS isn't commanding the valve correctly
So you're thinking that the MS is saying it is delivering 100%, but that the valve is not really opening 100%?

Certainly forcing the idle up with the screw will be a good test for that. As you say, if it will not go back down, then that is a good data point.

Is it possible to idle on screw opening alone (pulling the connector from the control valve). Can that be used as a maximum screw opening at, say 700 RPM?

Yeah, like mine runs 650 RPM with valve closed.
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Old 06-26-2014, 01:43 PM   #37
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that's what im thinking, yes.
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Old 06-26-2014, 01:57 PM   #38
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Originally Posted by DNMakinson View Post
So you're thinking that the MS is saying it is delivering 100%, but that the valve is not really opening 100%?

Certainly forcing the idle up with the screw will be a good test for that. As you say, if it will not go back down, then that is a good data point.

Is it possible to idle on screw opening alone (pulling the connector from the control valve). Can that be used as a maximum screw opening at, say 700 RPM?

Yeah, like mine runs 650 RPM with valve closed.
I definitely agree the MS is not opening the valve all the way, because it ran fine and idled up to like 1150 with A/C on on the stock ecu, before the idle screw was ever fiddled with. I just can't figure out what is causing this. Maybe changing the frequency is another idea?
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Old 06-26-2014, 02:03 PM   #39
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remove the diode and see how it reacts.
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Old 06-26-2014, 02:04 PM   #40
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Did you check your flyback diode if it actually works (multimeter test)?
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