Hello all,
im struggling a bit with the following problem:
Although idle seems to work nicely on most occasions, even on high electical load it does not dip that much, i have this problem:
as im cruising, if i step on the clutch and go to neutral while the car is still moving, and on top of that if i press on the brake slightly, the rpm needle as it drops towards 1000rpm, it dips, as if it will stall, then jumps up and settles to my idle speed.
i have tried various idle configurations to avoid this from happening, all unsuccesfull
I presume that this happens because as the car goes to idle config once the gear is out and TPS=0, there is not enough air allowed through the idle valve to allow for the idle settle properly without dipping.
I tried using min PW allowed up to 30-35% and above that it makes my idle really high so i dont like it.
This somehow helped a bit, but not much.
I tried playing around with PID and deadbands, again without any real change.
I tried altering the PW in hardware settings, again without real luck.
can you help me with this one? which area of the idle settings should i focus on?
what does the IAC delay do as well?
thanks
vasilis
what happens with the lambda while it goes down?
you need to be analytical and see exactly what the reason is for the behaviour,
not enough fuel/air , to much? to late?
ego works until 400rpm. the idle bin there is 1.01
when this happens, scenario is somewhat like this: i accelerate in gear and then immediatelly go to neutral and TPS=0
lamda on that point would be on the equivalent bin to accomodate and once in neutral, would go to the 46kpa bin which is =1.01
also the same happens if im on overrun and go to neutral in which case im lamda = lean and then goes to 1.01
i tried today PID settings with D=0 or 1/2 and it seems to be better. i do struggle though to have the idle lower than 1000-1050rpm though.
im wondering if i have to readjust the TPS a bit for that since this way i get no dips in my specific circomstances.
ill keep testing it for now and get back to you.
i think it was lack of air that causes this or PID control
i have tried for a couple of days the idle with PID: 28/12/2 and it seems much better.
however idle still has a specific issue with VEMS.
the higher the IAT, the higher the idle.
now this is something that needs additional adjustment with a table perhaps that has IAC and MAT as variables. Its the only way to keep it from climbing up as this happens.
Quote from: AVP on December 13, 2010, 08:00:42 PMthe higher the IAT, the higher the idle.
Lower your value for "refpos addition for MAT, slope".
its 3.1 now
should i get it even lower?
i reduced it to 1.2 4 step for now. ill recheck
You should also consider that you are probably not letting the PID control to have enough freedom to move away from the reference curve. Check the integral values in the datalog, to see if they rail against the min/max values you have set.
my integral values were set to 20 min/max and i reduced the max bit to allow the idle to settle lower if needed. i have always used small numbers here, maybe under this gonfiguration i should use higher.
PID, i tested lots of ways, starting with P only then working on but as soon as i introduce D into the equation, the problem reappears as i described it above. Also if i use high values on P and I, but relative to eachother, i find that idle may jump around violently on startup, so using values of 28/12/2 seems to work fine at the moment.
should i make the integral decrease limit even higher than 20?
I would use a larger integral limit. I generally use 0 for increase, and 50-80 for min, that's because I define my reference curve to be 200-300 rpm above the target rpm. The PID control then beds down the engine at the target rpm after first settling at a higher rpm. This behaviour has somewhat been removed and it is clear we need some re-factoring of how it works, it is discussed here:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FDamirMuha%2FIACintegral
Remember to take into account the effects of having ignition based idle control active.. it can hide problems with the PID tuning of the idle air valve.
yes im always concerned regarding the ignition based idle. so far whether i use ignition and iac getting after 2 or up to 9deg after the ignition to control idle makes no difference, so i have left it to 4deg after.
im going to put the integral limits in now.
right
on warm engine and MAT of 33-38 as the car was stationary i had 1030rpm which is ok, BUT as soon as the integral dec limit went above 20 (tried even 50) the idle speed went up, close to 1150rpm. best deal was with integral dec limit of 10. Maybe it has to do with the fact that my PID has low values as well: 28/12/2
the mat slope is on the second choice now, 0.8%. this way the idle is very good under high MAT conditions. again, changing the deg of advance that the IAC intervenes from 2/4/8 deg didnt have much effect on idle speed. It may have on changes of idle speed and the way it is controlled though.
What is your target rpm with a warm engine ?
940rpm
If i have ignition timing OFF, and PID 0/0/0, idle jumps to 1200-1300rpm. It is PID that slowly brings it down to the target rpm.
Please share a log file, lambda fully warmed up, no ignition based control and whatever PID settings you want and 50/50 for the integral dec/inc limit.
In the log, let it idle stationary, and then pump the throttle to bring it up to 3-4k and let it settle down to idle.
which gauges should i be looking at?
are you sure the integral has nothing to do with the I value? if you check the help file it says that it is related to the I value you use. This is something common for all PID settings.
i have to try and see if i have any log file, although it would be best to try something with the current settings rather than old settings.
although i settled for the PID settings that seemed to work for most if not all occasions, today it started happening again.
here is what happens: when im in gear and i take my foot off the accelerator, the car goes to full vaccum (15-18kpa if rpm> than 2500) , if at that point i go into neutral,----> although lamda should go from 20.1 (fuel cut) to lamda=1.01 at idle, it stays 20.1 all the way to the lower rpm point, until the rpm dips in and then jumps up again as it should stay on the idle area.
i have: fuel cut until 1600rpm,
fuel resume: 1500rpm
and i use fuel cut below 30kpa.
WHY vems does not resume the fuel as the rpm drops below 1500rpm although the map kpa is 30kpa? Is that supposed to happen?
i thought that the fuel was resuming below 1500rpm regardless of the kpa value that i set!!!
Even so, on various occasions im below 1500rpm and kpa above 30 and still i see lamda= 18.x something!!!
To try and see a difference, i set fuel cut 1700 and fuel resume 1600rpm and also the fuel cut below 24kpa.
it seems to be a bit better now, so ill recheck and report.
BUT im wondering why those figures dont always comply.
i also have the EGO correction Freeze enabled. Does that have anything to do with it??
post your log of this occurance
unfortunately i was out for a drive, i didnt make any logs.
all this is described by observing the LCD vems display of the lamda and map on the fly
Quote from: AVP on December 19, 2010, 02:33:59 PMi thought that the fuel was resuming below 1500rpm regardless of the kpa value that i set!!!
No, why would you assume that?
I find that it's usually conflicting to use both, so I use mainly rpm based overrun fuel cut.
Also remember, when you have used fuel cut the intake is very dry, it can take a while for the engine to play catch with the intake wall wetting.
so, what do you use? you set map = 0? and go by rpm only?
Quote from: AVP on December 19, 2010, 03:28:03 PM
so, what do you use? you set map = 0? and go by rpm only?
Of course.
Quote from: AVP on December 14, 2010, 11:27:53 PM
which gauges should i be looking at?
are you sure the integral has nothing to do with the I value? if you check the help file it says that it is related to the I value you use. This is something common for all PID settings.
i have to try and see if i have any log file, although it would be best to try something with the current settings rather than old settings.
Why are you asking the obvious? The IAC gauges are what you should be looking at, bring them up. IAC int, duty cycle and target rpm are the main ones of interest.
What do you mean that I'm sure the integral has nothing to do with the I value? Of course it's related.
If you minimize the increase/decrease the PID has no impact on the idle control. If you check the target and actual rpm, and the IAC int value you should be able to draw a conclusion pretty quick on what's happening.
Share that log that I was asking about before.
i see
i will try and see if i have a log that has some kind of these circumstances and post it up.
i wasnt aware of these gauges so this is why i havent been paying attention to them. I was tuning the idle the same way i did on megatune, byt change and feel.
i will also see if i do the same with the fuel cut issue, maybe it will be better.
About 90% of all datalogged variables don't have a gauge, you have to bring it up - nothing new here.
Some gauge group screens have more or less gauges of interest, depending on what the intended use for that group is.
Example VE tune is for VE tuning, not idle tuning - but I use that view most of the time and just right click on a few gauges and change them into whatever I need to monitor.
http://www.box.net/shared/nuskyfkxl7
here is a link to a log that i have done a few days ago, and the PID settings i have there are the same as the ones i have today.
only difference today is the fuelcut and resume rpm and the map kpa to 24 for fuel cut.
please explain to me the iac int, and rpm target as it goes through the log.
i noticed that the rpm target somewhat follows the actual rpm when not on idle. why is that?
has anyone seen the log?? ???
I checked it out, your "IAC int" value is railing at -20 trying to do it's best to lower the RPM down to the target RPM.
Your ignition based idle control is what's doing most of the work, but it's clearly not enough.
20 deg advance and 14 deg retard is a lot of power to this function.
I would limit it to +/- 5 degrees at most unless the setup has no idle air valve.
The IAC close delay closes the valve completely after 4 sec of the throttle being above the idle threshold. I usually set it to a much higher value, like 20 secs which means I won't notice it much when it's closing. On a boosted car it could be important to allow the pedal to completely control the air flow, not that I've given it much thought..
Your Idle air reference table looks the opposite of what I would expect. Less duty at low temperature, and more at high temp. Are you sure it's wired in correctly? Because you haven't given it any power to do much about the idle via the integral increase/decrease so that you may not have noticed this fact. In your case the reference duty cycle table is what dictates the idle speed the most + the almighty idle ignition advance control.
Listen.. set integral increase/decrease to 0.
Disable the ignition advance idle control.
Bring up gauges for target rpm and idle air duty cycle.
Open the dialog for the idle reference duty cycle table.
Cold start the car. Change the cells to have duty cycles so that your idle speed is 300 rpm above the target rpm in the gauge.
Watch the target and actual interpolated (from the table) duty cycle and what it does to your current engine speed.
It's very important to get the correlation that a higher duty cycle = higher RPM. If this isn't true, you must set the idle solenoid channel to it's inverted function to make any kind of idle tuning possible and make sense.
Make sure that you see that the ignition advance during idle is always what you have set in the ignition table as the advance greatly affects idle, just what the idle ignition advance control does when activated. Hopefully this will be replaced by a proper table just for the ignition advance at idle.
When the reference table is set, use the warm idle duty cycle for the cranking values for both hot and cold engine - that usually works out well for me.
Now you can enable the idle ignition advance control if you like, good values would be 5/5/25/4 (top to bottom). Then it's time to play with the PID and make it behave.
as i was using in megatune, i had improvised a system where the idle was ignition controlled mostly during warm up to keep the revs up, and then the ISV came into play to some good extent.
regarding wiring, since you have already mapped an S2 you should know that there is nothing that needs done with wiring on the audi 5cyl engine, as the VEMS is plug and play. So i havent touched any wiring to make it become opposite in the ISV reaction.
as i mentioned before, if on these excact settings i use integral limit higher than 20-25 the idle rises, it does not fall.
i will try to give your idea a go to see the reaction i get.
I have done mostly S4, the only S2 cars I have played with have had custom intakes with no ICV.
Compared to an S4, you have half the duty cycle in your reference table. It should be more like minimum 35-40% and 45-50% when cold.
Edit: it could be that your TPS is adjusted to have a higher idle position..
well with the settings i have, my ISV if i take it above 30 it rises the idle and anything above 40 it makes it oscillate like crazy.
mattias,
if you use ignition +/- 5, what value do you use for deg for enabling IAC ? i presume fairly low so that IAC controls idle most of the times, correct?
With +/- 5 degrees control, I use 4 degrees for enabling IAC to let the ignition advance take care of the small variations.
When you raise to 40% duty cycle and the idle starts to oscillate, figure out why. Check the lambda (VE table problems) and ignition advance. The overrun fuelcut could be the cause, I don't remember at what RPM you set it. The duty cycle that is ok with a cold engine might take it up to the set overrun fuelcut RPM limit. Either way, it was just an interesting experiment, clearly higher duty cycle brings higher RPM which is what you want.
You should also check if the throttle is open a bit, that would explain why you're using lower values than I'm used to with the Audi S4. It could be just right as well.
i have readjusted the throttle plate and that is definitely completely shut.
my overrun fuel resume was on 1500rpm,
now when previously i had disabled PID control and ignition based idle, the idle speed was at 1400rpm and the more duty i gave the higher it went. BUT once i also went below 20PW it also got higher. It stays lower in general when i keep it between 20-30PW.(which is why i have the values i do on those areas.
it is interesting to do this experiment and i will do so and report back.
at least now that i have a working idle so far with my settings, i can try and see what else works.
however other settins such as the ISV hardware settings, also come into play. what do i do with those? do i leave them at 35hz as i have now and min/max as i have them?
i changed the kpa for the fuel cut to 0 and it seems to be much better.
Quote from: AVP on December 21, 2010, 11:17:53 AMhowever other settins such as the ISV hardware settings, also come into play. what do i do with those? do i leave them at 35hz as i have now and min/max as i have them?
In a testing phase like this you should set the min/max dutycycle to 0 and 100%, the limits are there to stop the PID to move above/below.
It's obvious your valve is responding only within certain limits and not in a linear fashion, this could be due to using improper PWM frequency. Try to use double the frequency and see if both the useable dutycycle range and max/min rpm changes. It's likely that the proper frequency is in anywhere from 50-100 Hz.
(don't confuse yourself or others by using "PW" - you meant to say dutycycle %)
You would be amazed of how many diff hardware settings I have sen being used successfully on the Audi. Anything fro 25 Hz. To 250.
I use the acronym PW because that is what vems says when you open the table.
Quote from: AVP on December 22, 2010, 09:54:09 PMI use the acronym PW because that is what vems says when you open the table.
No it doesn't, it says PWM and the column header says "RefDC (%)".
well, it should say what it should mean, why the 2 meanings?
anyway, this is a different topic mattias.
as i said, it appears that managing idle has lots of solutions. I will try and find some time to test your theory of calibrating the idle and once i have some results i will report back.
It says exactly what it means, and it doesn't mean two different things. PWM = Pulse Width Modulation is done with a specific switching frequency. The duty cycle % refers to the 'on time' vs 'off time'.
http://en.wikipedia.org/wiki/Pulse-width_modulation
Looking forward to some idle testing results from your S2.
i know what duty cycle means but thanks for the info.
when i have more info from the rs2 i will post them up
reporting back from the idle tests...
I did what Mattias suggested, that is ign. idle disabled, integrals all to 0, PID i left it as it is and brought up the idle gauges.
Indeed on cold start the idle DC can be brought up to 40ish to start with and it works fine keeping the idle to the idle speed i want it.
The big suprise though is on warm idle.
On warm idle, any values on the DC below 28 start to bring the idle speed up gradually, from 1050rpm to 1400+ rpm and the lower the DC the higher the rpm goes.
I tried the inverted channel, and it did the same but on the oppposite DC values, ie: idle speed was at it's lowest on 70ish DC and started to go higher for any value above that (80-90 etc)
i eliminated the fuel cut rpm areas and that eliminated the oscillations i was getting as the rpm idle speed climbed, but that had no effect in the ability to manage to lower the idle speed anywhere close to my specified speed of 920rpm.
I tried different values of IAC Hz, with no effect. Anything from 25 to 250 did not change that behaviour.
It is this fact which makes the above behaviour from the IAC integral limit. As mentioned before, once i used IAC dec.limit anything above 10-15 the idle speed started to go up, and that was because the integral was taking the DC into low 20 values and that brought the idle speed up again, as i noticed from manipulating the reference table curve.
So my question to you guys is, why am i not able to get lower idle speed with the IAC alone by giving lower DC values as it should happen?
My setup has the reversed inlet manifold (wagner) and the idle valve is situated in an aera similar to the OEM position. 70mm TPS instead of 60(OEM) and the TPS has been adjusted to be as shut as possible.
when i enable the ignition based idle and the rest of the settings i can get the idle speed a bit lower, but the spark goes into sometimes 5deg when in OEM motronic setup, i usually never goes less than 8 and idle speed is set to 800rpm.
any explanation is welcome.
i do have a log,but it may not make much sense as i had to start and stop the car's engine a lot of times and it may be broken into smaller pieces as a file.
vasilis
BOSCH two pin IAC has mechanical "limp home" mode. Without current it opens in opposite side allowing to keep idling. Usually about 300rpm over normal when warmed up with no load.
Usual DC on 20VT is around 50% (if you have diode in parallel to IAC). Somewhere at 30% IAC is fully closed. Below 25% it opens again. But on opposite side.
Your situation means: engine get air somewhere else. It should die at 30%. But engine has enough air for idling.
First thing to check is throttle stop screw. Then anything else. Incluiding air leaks.
Gints
i see
i do have a diode working with the IAC.
i have also checked the TPS from the screw and it is completelly closed, so it is not that.
I dont seem to have any leaks, BUT: i do have a dump valve next to the throttle position sensor which on idle it is part open. So air may be drawn through there? that valve is BEFORE the TPS, so as the idle control valve is on that area as well, could it be drawing more air than required and therefore not lowering the idle as it should?
on the other hand, if the idle valve is completelly closed on 30DC, then if there is an air leak somewhere, should it be after the TPS?
here is a photo of the ISV valve at the backround, and the dump valve in front
(http://i117.photobucket.com/albums/o59/vasp3690/030820101337.jpg)
here is the engine photo
(http://i117.photobucket.com/albums/o59/vasp3690/030820101336.jpg)
Dump valve did not feed air to the engine. It simply bypass turbine.
Block IAC hose with plug. Engine should die. If it still works, search for air source.
Thanks Gintis
after a bit of search, i did find a torn vaccum hose which i replaced. Now i setted up the DC reference curve as mattias suggested.
However i still get the idle speed getting higher as the IATs get higher, and even with the refpos in idle general settings disabled.
why is that happening?
what Hz is best used?
when i try to run the car with the ign.table disabled, the idle valve cannot keep the idle speed low enough. Even at 30% it is still running. Surely there is no other boost leak now!
here is my big question:
reading from the wiki as well, it appears that when the IAT is going higher, the idle should usually go lower!
in my car, the opposite happens!!! i get higher rpm speed as IATs get higher!!!
Did you try block IAC hose? Still runs? Then you have a leak. Legal (trough trottle) or illegal (hoses, O-rings, seals etc).
Usually rising IAT leads to lower rpms. Simply because of less O2 molecules passes trough same area.
it is dark outside, so i couldnt block the IAC completelly.
the Throtle valve may not block the area of the TPS 100%, but from memory it is a very narrow opening that remains, less than 0.1mm
if usually rising IAT causes lower rpm, then why is the opposite happening in my engine?
went at it again. Definitelly not visible leaks from hoses etc
when i tried to remove one of the vaccum hoses from a T piece that connects the rear of the inlet manifold to the dump valve and the hose goes into the ECU in the car, the car momenteraly almost died!
i quickly reconnected the hose and the idle speed was reached once again.
Hi
You could try my settings.
Fit a diode near the IAC
use highest frequency
Her is a log: http://vems.dk/vems/v3.3_n002087-2010.12.24-11.16.23.zip
Peter
Diode is fitted already between the oem plug and the is valve
peter, i cannot open the log file, can you try and resend it??
Try this then http://vems.dk/vems/v3.3_n002087-2010.12.24-11.16.23.vemslog
Peter
Do the test that Gints told you about, and set the min limit DC % for the valve to 30% to prevent it moving into limp-home mode.
You must let the valve control the idle completely to make the best use of the adjustments.
Quote from: AVP on December 28, 2010, 08:44:02 PM
went at it again. Definitelly not visible leaks from hoses etc
when i tried to remove one of the vaccum hoses from a T piece that connects the rear of the inlet manifold to the dump valve and the hose goes into the ECU in the car, the car momenteraly almost died!
i quickly reconnected the hose and the idle speed was reached once again.
Most probably from that T-piece goes hose to the MAP sensor. Otherwise it require deeper inspection.
How it becomes that you can't block IAC hose? You always can!
There is no matter to try different settings until too much uncontrolled air goes to the engine.
BTW 0.1mm could be enough. What about stop screw?
Engine has no more MAF. So easy way to check flow trough throttle is block it. I usually do it by palm. But it is bit painful. So you could prefer some similar alternative.
Regarding frequency. Valve works quite good on different frequencies since true PWM involved. I use lower frequencies like 75, 100Hz. Then valve has less chance to stick. It vibrates a little.
Also very important to add, since I failed to notice the comment about the T-piece earlier : You must never connect the MAP sensor hose anything but directly to the plenum. Sharing signal line with the dump valve or wastegate is not practical, those devices require flow while the MAP sensor is basically static, which can cause false readings in the MAP sensor signal.
And also it is important for your turbo that dump valve has direct, well breathing connection to plenum. Valve should work as sharp as possible. But any additional volume (MAP sensor hose in this case) in dump valve hose works like a damper. As result valve get lag.
Guys thanks for the answers.
to get something clear because you have been telling me a few times without reading my posts:
TPS plate screw has been adjusted to the point where it cannot be adjusted any more!!!!!!! OK?
now that we have that clear, i will change the vaccum hoses to ECU and dump valves ( i have 2 of them) so that they do not interfere. However, even motronic picks up the signal from the plenum this way( throuth a T piece) and there are no problems there.
The reason that i cannot easily block the IAC valve hose is because of the position of the valve in the engine which makes it very difficult to fit my hands in there to manipulate it. Did you see the pictures i posted? Yesterday in the dark i could not do it. I will try and do it today.
The T piece that i momenteraly removed, if that was the problem and it is leaking, then why did the car almost died? Shouldnt it increase the idle speed once i took it to the air completelly? By removing it i basically generated a larger boost leak! But instead of the idle to go higher, it almost stalled. Is that what is supposed to happen?
@Mattias: you never connect a vaccum hose from the plenum or ECU to the wastegate anyway. But most of the times you do connect a boost gauge for example to the hose that goes to the ECU without problems.
Unfortunatelly i have 4 vaccum exits from my plenum and i need to connect to those: FPR, x2 Dump valves, ECU, Methanol injection, Carbon canister. Can you advise which are OK to connect together so that i use the T pieces there and eliminate probable malfunctions?
In any case today i will try these:
1) block the IAC hose to the plenum: if the car still idles but does not reduce any idle speed, then this will most likely be a leak after the plenum.Correct?
2) If the throttle plate leaves a small amount of opening regardless of the adjustment screw there, then there is nothing i can do than to order a new throttle plate which seals better, correct?
3) Since i now have 30%Dc on my settings to keep the idle speed as low as possible, and 100Hz on the speed, it seems that settings wise, this can no longer be adjusted anymore. It looks like i either have any of the 2 problems above to solve.
If you momentarily disconnect the T-piece that connects the MAP sensor to the intake, then that will make the MAP sensor see atmospheric pressure and the intake actually has idle vacuum and the engine will run very rich and stumble.
The FPR, boost gauge and ECU MAP sensor don't need "flow" in their lines and can be connected to the same line. Generally these are also considered quite vital and if possible they are given their own signal source, but do it right and you should be ok.
The Motronic heavily relies on the AFM, the MAP sensor and intake temperature sensor (speed-density) are secondary in that case.
Good luck with the testing!
It's better to make decisions once you have tested more.
Unless you have done a proper intake pressure test, you should. I posted this which I wrote on another forum :
http://www.vemssupport.com/forum/index.php/topic,1451.0.html
It is not easy for me to do the whole method for intake leaks. I have looked for boost leaks in the past and also all of the intake pipes and intercooler have been checked recently.
My problem exists after the throttle valve and the means the manifold and all the vacuum hoses connected to it
I rerouted the vaccum hoses and checked them. No leaks there. I now have a dedicated line for the ECU, separate for FPR, separate for PCV and the one that goes to tha carbon canister, i used for the methanol and dump valves.
i redid the PW reference curve and idle works fine, BUT still need to keep it at 30DC in order to achieve my 950rpm.
I did not check the ISV valve by blocking the hose there, as its too cold to try, but i think my problem is the throttle plate. When i had it machined to 70mm, i distinctly remember a small area which was always open, even with the valve totaly shut, so i think i may have to have a second one made.
On one more test and ride, i noticed that the idle is sort of keeping at bay, at no more than 1000rpm even on higher IAT (34+) and that is good at least.
Vems is manipulating the valve as it should and does not need to be inverted. I think that if i manage to make a second TPS with better seal it will solve the problems. We shall see...
i managed to see the log file Peter. Thanks for that,but i cannot use the settings you have, as due to the throttle body flap issue(i believe), if i use 41% DC for the warm area, i get about 1100-1150rpm idle speed.
So ill stick with my settings for the time being and wait until i have a second throttle body fixed and fitted.
im going to fiddle around with the TB tomorrow as i think i can adjust it a bit more if i modify it slightly...
after a bit of fiddling, i ended up going from 30 to 33DC on the idle curve. I think that is ok for now.
a small update
idle is very good now 99% of the times.
after a bit of testing today though i noticed this.
Although PID works on most occasions with minimal dip of the needle when offset of idle( ie small blips of the throttle), and with electrical load as well one, i tried this: i turned the ignition based idle off, and the idle even without the press of the pedal was slowly going off balance, and ever so slightly trying to oscillate.
I believe this is down to PID settings and it would require more PID fiddling, but if i fix the PID somewhere where it is ok for the idle then, would turning the ignition timing idle on again make a difference? would it be more stable?
Is this the way the idle should be tuned? or with the ignition timing ON always? and then PID tuning?