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Closed loop idle too early?

Old 12-05-2015, 03:21 PM
  #41  
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Originally Posted by patsmx5 View Post
Again I'm new to this, but why would you want closed loop to register negative RPM changes to disable it? If it did that, it would turn off closed loop if the RPMs drop and it tries to die on you- the opposite of what you want!
Swing and a miss.

Aidan's problem is closed loop turns on while he's crhsing at 1800 rpm. Closed loop can't bring 1800 rpm down to idle, because its not idle. When it actually goes to idle the idle valve duty is way too low because its been trying to slow down 1800 rpm when it shouldn't.

Pid disable rpmdot would kill closed loop if it accidentally engaged like this, and if the initial value table were tuned right then it wont stall and'll be close to the proper idle value.

I will check to see if my ms2 will disable on negative values here in a bit.
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Old 12-05-2015, 03:22 PM
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Pat, I do understand your take on it. And that very well may be the developers idea. Just wanted to check with the older code to see if it used to be different.
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Old 12-05-2015, 03:25 PM
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On ms2 I can't set pid disable rpmdot lower than 200 rpm. If rpm drops harder than 200 rpm/sec near idle values ***** about to stall unless the valve is opened.

I'm nearly certain that's what it's for.
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Old 12-05-2015, 03:27 PM
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In my mind its this.

Set the PID disable to just above what your normal idle variation is, when turning on loads and whatnot.

If it goes above normal, **** has hit the fan, and add dashpot and go to initial value.
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Old 12-05-2015, 03:32 PM
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Ah, makes sense. I'll try messing with that on my car and see how it works. Can you post your MAT initial value table?
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Old 12-05-2015, 03:34 PM
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I can, but its barely tuned at all. Works somewhat decent.



For reference my min and max are 29 and 68
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Old 12-05-2015, 03:36 PM
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Thanks. I gotta fix what I believe is a failed clutch master cylinder, but then I'll mess around with some idle settings later. If I figure anything out I'll post it here. I have it using last value, not MAT table so I'm gonna set that up first.
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Old 12-05-2015, 03:48 PM
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The problem with use last value is that it would still stall Aidan's car. It thought 29% idle valve were proper at 1800 RPM, then he stalled. If It weren't for the startup idle valve adders the thing would try and pull 29% DC on entry next time, which we know can cause stalls. (say he saved it stalling, now the car thought it idled fine and just left CL idle, and it's going for 29% next time first ting) I think it also causes the problems we saw Curly mention the other day, that is stacking dashpot adders if you blip the throttle many times in a row.

It basically exits closed loop when you blip the throttle, then goes back in while the RPMS are on the way down. If you blip the throttle again before dashpot is gone completely you enter too high after the next blip.

Tuning the initial value table is a pain, but CL idle ain't worth anything without it. My strategy like I said earlier is never closing the valve, it always tries to apply an idle valve value based on the initial table if CL is engaged or not, that way if my dashpot isn't completely out of the way I won't be adding to it, I only ever add to the initial valve table, crazy consistent values!
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Old 12-05-2015, 05:45 PM
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I wonder if this is caused by my TPS not returning all the way to zero, because its a wells tps that doesnt fit the throttle body perfectly?

On the scope there is about .02v p-p noise. And when tuner studio reads different values when i close the throttle the scope reads different voltages too. ****.

Deezums let me know when you check the negative RPMdot. I want to report it as a bug to Ken/James.
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Old 12-05-2015, 05:51 PM
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So it's a TPS issue. Try all the suggestions already posted here. Replace it if they don't work.
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Old 12-05-2015, 05:57 PM
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I played with the adjustment some. No go. I'll try again in the other direction. Ugh, do not want to replace this thing again. I'm on like the 3rd one.

My issue would be solved if the rpmdisable worked both ways.
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Old 12-05-2015, 06:57 PM
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I think my disable RPMdot is working on negative RPMdot values.

I also incorrectly assumed MS2 wouldn't let me set less than 200rpmdot max, I can go down to 100, and I've had it set as low as it'll go.

I dropped to around 650rpm in this log around 100 seconds and recovered using fuel and timing alone, the idle valve didn't move the whole way through. You might be able to fix the stalling, while still having dips at least.




This is my valve at the min duty cycle in 4th gear, I just pushed it into neutral and coasted. Idle DC came up before passing my CLidle target.

I don't use PID either, it suuucks. I love this dummy mode, if it's low it adds, if it's high it takes. If I tell it to slow the **** down and let things settle between adjustments, it does! I run EGO correction the same way.



Is there a flag or ADC for CLidle active in a MSL? I can't find it.
Attached Thumbnails Closed loop idle too early?-wq0sqbe.jpg   Closed loop idle too early?-waq9qz7.jpg  
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2015-12-05_16.22.02.msl (3.72 MB, 92 views)
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