Closed loop tuning is witchcraft
 

Hello,
I have been trying to keep my car from dying while turning on the AC. I did tune in open loop first, which was fairly easy, but the AC would still stall the car and it would shake like hell and die on decal in neutral. I'm tuning closed loop now, and its witchcraft! I don't want to give up on this and run my car in open loop, which runs at 3000 rpm at idle now after I've made adjustments for closed loop? I have been reading a lot on this forum the last few days and made lots of progress on my car, I'm overlooking something, or you guys and gals may look at my tune and think im an idiot, which is what I want you to do. Please help a fellow enthusiast out if ya will and it will be greatly appreciated.

your open closed values are preventing the code from working.

https://cimg0.ibsrv.net/gimg/www.mia...40e3742885.png

your idle valve is locked at the 58.4% setting.

your closed sloop settings in general are just bogus.


what year car?

The car is a 93 1.6, N/A stock. That setting at 58% is really the only way to keep it idling and not start to oscillate up 2200 rpm. I did try to adjust fuel in the VE table but nothing helped up or down. I could hear the idle valve actually pulsing (opening), rather loud before settling on that %. What should my open /closed % be? You say locked, so I'm assuming my %'so are fighting each other?

If it idles at 3k on open loop closed loop is going to fix it... Fuel and timing need to be dead nailed first, can't stress this enough. Think of closed loop as added air, thats all. Your closed duty is higher than your open duty so the ECU can't move the valve. Follow this tutorial here Tuning Idle Valve - Ms2 - Guides: Forced induction - MX5Nutz Forum and it will get you pointed in the right direction.

Stealth, your suggestion helped somewhat and I thank you. While doing the valve test I put it at 100% and worked my way down to my target rpm=1000, and ended up at 85%, set the test at 30% started to go down and the car rpm went down and wanted to die. So, I put the test at 0% which was about 2500 rpm??, worked my way up through the percentages; rpms went down but car never died and I ended up at 58% for my target rpm. The reason I did the test to my target rpm as opposed to the instructions is I don't have the parameters for min and max closed loop rpm. I have firmware 3.4.2, I don't know how much/ what was changed from previous versions. My MS2PNP shipped with 3.3.1, after setting my base timing I cycled power to remove from fixed timing and a whole slew of errors occurred and I just installed 3.4.2, and I used the 3.3.1 base map for my current tune:dunno: Do you think I have a faulty Idle valve? it worked perfect with my stock ECU.

do you not see your open is lower than your closed? the valve cant do anything but sit at 58.4%.

youre not using closed loop, you're using a static value for idle speed.


you should be using 25% for closed and 60% for open. and I'd start at 500 for my closed-loop gain, and i'd lower dashpot to only about 3%.

try the attached map and tell me if it's not better.



also: who built your MS? Is there any reason you have a/c idle up active using launch in, but with no active output? The whole point of the a/c idle up code is so the ms can control when to turn on the compressor.

Braineack,
The changes resulted in a 2200 rpm and my closed loop idle light was on, I'm ok with this for now as it held all loads without dying and dropped to 950-1000 rpm. Maybe VEAL will correct some of this. I bought the MS2PNP from DIY Autotune, I was very confused when I received it b/c I literally spent hours looking through the thumb drive for the base tune and there was none....lol.

So I got it to to idle at 1450 with 40% closed DC and 71% open DC and handle all loads without dying with a final rpm of 950-1000, not bad. I did not touch the PID gain controller, but my car did get pretty hot and I heard a pop from the Idle valve as it started to die? I'm letting it cool off and i'll let ya'll know if its fried or if it just got tired from all the adjustments from this weekend....lol. Tuning is so much fun.

It's not clear what you're doing with the duty-cycles, other than hitting an arbitrary rpm target based on arbitrary load.

The "Closed Duty" and "Open Duty" are what the PID controller uses as parameters to figure out where to set the DC.

It's flexible based on the car/idle-valve, so it's up to YOU to figure out the lowest DC value that still moves the valve, and the highest DC value that the valve will move at. ie: If you idle at 725rpm at 20DC, and dropping it to 19DC goes down to 700rpm, then keep going until the rpm values no longer drop. That final # is your 'closed' setting.

Then do the same for the open setting at the high end (start around 60 or something and keep going up), it should max out around 3-4k rpm and annoy your neighbors. Once you have the lowest and highest values plug them into the PID settings, and then you can start tuning the idle parameters. You're literally telling the controller "these are the lowest and highest values you have to work with, have at it".

Any ideas on why my idle valve would have high rpm ( 2200- 2500) at 0% DC during the Idle valve test, and stall (starting at 700 rpm) and die at (300 rpm) with 100% DC during idle valve test? According to the MS2 setup manual 100% should be max airflow. My idle valve is set to normal where 0%= off.

What DC% provided the lowest RPM and what DC% provided the highest? You're going to be using a roughly 30-40% range out of 0-100%, you just need to find the values that actually cause a reaction in RPM.




your Idle bypass screw should be pretty much fully CW.