Closed-Loop Idle: Car Dies Coming to a Stop

[blasphemy101]

I switched them around and all it did was reverse the 'direction' of the switch (higher throttle = lower output).

I noticed it reads fine with the car shut off (accessory/ecu on), but it won't detect light throttle with the car running. Sounds like an electrical issue. Any ideas?

[Q5Quint]

Well, technically you only need the tps for accel enrichment.

I am using the stock on/off switch with map based accel on ms2 and it works just fine. Idles great and everything, but looking at my file it looks like I am not using any of the closed loop settings you are speaking of, only warmup idle settings. (pwm idle duty cycle)

This was one of whodwhos files so it may just not be displaying because I am not connected to the car or something, but I always thought the 'high-idle' valve never opens unless its cold and you need a high idle.... but your settings are implying that it opens/closes from 600-1400rpm based on..... something? PID? Is this so it adds some partial throttle when you shift?

I read through the megasquirt manual and it doesn't mention those settings at all... but maybe I was in the wrong place http://www.megamanual.com/ms2/tune.htm

Looking at my settings I am going from a 45 to a 34 pw on the idle valve based on coolant temp. The car was a bit harder to start this winter so that may not be enough, but it seems to generally work 90% of the time just fine so i haven't messed with it.

I probably idle at 800rpm or so with everything closed, and when it is cold maybe 1000rpm. I will mess with the settings tonight and see if I can figure anything out.

[blasphemy101]

Would you mind posting a screenshot of your Idle control settings and the PWM warmup table?

Like you, I've been able to get along pretty well without needing the TPS. I'm just trying to step up into some of the features a variable TPS offers.

[whodwho]

Are you trying to get CL working or switching to warmup mode?

I would start with warmup mode and get the idle as stable as possible before trying CL; any instability just aggravates oscillations

This may help the most for you if you are noticing it trying to drop out when coming back to an idle:
You can use idle advance to help can catch it from dropping out; set your advance on your timing table at your idle bin and the one above and below* a bit advanced by a couple degrees ~18ish then have your idle advance table a couple degrees lower ~16ish then when it comes down to idle the advance will be up and after the delay will settle to the lower advance. (Keep the idle advance delay shorter than the CL delay if using CL)

*You can also try set setting the advance a little higher in the bin below where you idle at to help spring it back up(if that makes sense)

The idle valve:
For the idle valve set it 3x freq
Switch the valve mode if the valve is reacting opposite than expected
set the crank to run - 3-5

For warmup mode:
set the PWM cranking duty to ~ 35-40 across the board or so the idle is 100-200 rpm higher then desired RPM(you can fine tune this later)
set the PWM warmup table for whatever it needs to hold the idle slightly above final desired RPM(~100-200 RPM higher) for non warmed up temps
set the last bin or two for what it needs to keep the idle at desired RPM

For CL: (Don't even bother if you are not really close to tuned and have a stable idle and have had it running on warmup mode first!)
Use 3.2.5 firmware or higher( I didn't have the best luck with it in earlier versions)
Make sure you have TPS calibrated and have a good stable 0% signal when closed

Try roughing in these settings and see if it will get you close
idle valve open - 75
idle valve closed - 25
idle activation RPM adder - 250
idle activation TPS - 1-2(has to be under what closed throttle TPS%)
Dashpot adder - try 2

min duty for PID - about 5-10% less than the lowest duty you have seen to make it idle - This could aggravate your dropping out if set too low - try ~30-35
RPM with closed - ~300
RPM with open - ~2500-3000 this will effect resolution
PID delay - ~2 (needs to be more than idle advance delay if you are using it)
Crank to run taper - ~3-5
PID ramp - ~2
PID control - 100

PID: (don't jump to change these too soon, none is better than too much)
start with all set to 0 and try seeing how close it is before changing
Bring in 'I' if not getting near target try around ~20-40 if needed
P - bring in if not catching dips from sudden loads (I really don't think much is needed, I don't use any)
D - you shouldn't need anything higher than 0

Lockout: (I have not needed to work with this one much)
PID lockout rpm - try ~80
PID lockout decal load - try ~35

PID disable
RPMdot - try 300

These are just rough setting to try getting you going they are not solid settings guaranteed to work and have a rock solid idle ;)

Good luck

[blasphemy101]

Well, I've been running Warm-up for the last couple of months. It's been pretty stable, but like I said, I'd like to try to move on to CL. I only asked for someone else's Warmup settings so I could compare and see where mine might be improved while I get my TPS sorted out.

Since finding the TPS issue, I'm not entirely convinced my CL settings are the problem - the seem comparable to others I've read about. I'm going to try another TPS to see if that solves my problem. I'll post back here once I make some progress.

Thanks!

[whodwho]

Did you change up the TPS pins at the connector?

EDIT: and I know there were requests but I don't think it was ever implemented - PWM warmup settings are not used while in CL mode

[blasphemy101]

Did you change up the TPS pins at the connector?

EDIT: and I know there were requests but I don't think it was ever implemented - PWM warmup settings are not used while in CL mode

Yep, I did. See below.

Yeah, I wish they gave you the option to have the PWM Warmup settings control Warmup instead of letting CL handle it. It would take out some of the overload of all the new settings for newcomers like me.

I switched them around and all it did was reverse the 'direction' of the switch (higher throttle = lower output).

I noticed it reads fine with the car shut off (accessory/ecu on), but it won't detect light throttle with the car running. Sounds like an electrical issue. Any ideas?

[whodwho]

ahh, missed that

[blasphemy101]

ahh, missed that

No worries. Like I said, I'm going to try a new TPS (and probably switch the wires back) to see if that makes a difference.

[whodwho]

Are you using a M5x based one? They will need to be switched, the ground is going to the wrong pin when in the stock position

[Q5Quint]

Can confirm my m50 tps on my old setup had pin issues at first. When I saw ms2 didnt need it I decided to stick with stock and thanks to mr Whodwho it has been running excellent for about a year. Also I just realized how lazy I have been keeping up with updates etc this time around.