Hello everyone

I just installed a MS3 Basic from Reverant, I am running firmware rev 1.4.0 with his basemap, most of the changes are VEAL related. I haven't changed any startup settings yet as the car does start everytime after 2-3 seconds cranking, and I don't want to change any variables just in case some of my issues are related to idle settings. All of these issues and datalogs were taken with the car fully warmed up, my base idle is set, my wideband is calibrated, the air temp sensor is calibrated, and everything seems to work properly other than these things. Car is a 2002 NB, naturally aspirated, typical bolt-on mods. I haven't touched the idle screw and I don't plan on it unless I need to.

I have 3 questions,

1. When I try to test the IAC valve under 'Output Test Mode - Idle Valve' I can change the valve position to 18 before the idle stops dropping any further, however when I raise the valve past about 55, the idle starts hunting, somewhat uncontrollably between 1700-2300, going back and forth. I thought this was EGO kicking in, or something like that, so I turned it off temporarily and tested it, but the issue still occurred. I didn't grab a datalog of this, however I will recreate it next time I drive the car tomorrow and grab a log. The closed loop idle settings Rev has are 18 as the minimum, and 70 as the max, so the minimum was right on. I don't know how vital the maximum value for the IAC valve is anyway, as I see no reason I would want to idle at 1700+ RPM. I will be changing the 'Use Last Value or Table' to Use Table once I determine the min/max values of the IAC stepper, so I can get more consistent idle results.

2. About half the time I start the car and I check the logs with MLV, it reports cylinder 3 as knocking when the car is at 400rpm. I suspect this is a false-reading due to my rough starts, most likely attributed to my idle settings not being dialed in perfectly. Does this sound correct, or is it possible that my car is indeed knocking right as it starts? Here is a screenshot of the logged "knock", and I have a datalog of this attached. Beware, I don't know how to trim the log files, so this one is 10 minutes long, the knock is at the very start. Here is a screenshot as well of the knock in MLV



3. When I turn on my A/C at idle, the car will hunt for its idle, and it won't stop until I turn the A/C back off. I suspect this is related to the PID settings that the basemap ships with, however I haven't made any changes to the values yet to test this theory. Total noob guess, turn down the D under closed loop idle settings? Datalog is attached, 45 seconds worth. A/C idle up is enabled, settings below. It seems like the compressor is kicking on and off every few seconds when this happens.


And the closed-loop idle settings


Other than these things, the base tune has worked great. Started the first try, and it hasn't ever stalled out on me despite idle oscillations with A/C.

I have attached my current tune as well if any of you want to critique it. My AFR Target & VE tables are pretty rich in the interest of safety, I will eventually lean the table out once I get these issues fixed and am sure it isn't knocking anywhere.

Thanks!

 

I went out and got a log of the idle valve test, when I change the stepper position from 18 to about 40, its normal. Once I hit 1700 RPM/a value around 50 it fluctuates, the AFRs seem to freak out, and I can't tell the difference in RPM when I continue to raise the stepper position. Is this normal, or is there something I am missing to find the maximum value for the IAC valve?

Regarding the A/C idle hunt, I warmed up the car and drove with the A/C working normally with the current PID settings on the tune, when idling and when driving. Once I stopped the car, and cycled the A/C by pushing the button on/off, the idle started hunting. I tried to remedy the hunt by changing the PID settings under 'Closed-Loop Idle PID Gains", moving the slider from 0-500, changing P, I, and D to lower values, however no matter what settings I changed & burned to the ECU, the hunt continued. When it does hunt, the A/C doesn't cool at all, and I slowly begin to melt. The only way for the A/C to cool is for me to start revving the engine manually. A log of this is attached as well, I think I am looking at the wrong tables to change for this issue.

I recorded the wrong way showing the issue, I am going to look at guides on how to fix idle hunt issues and see if I can figure out what else to change.

I also just realized I never calculated required fuel after changing the injector CC, whoops. Going to do that now and see if it is possibly related.

 

When you hit more than 1800rpm when stationary with no throttle, the overrun fuel cut kicks in. Disable it if you want to test things.

 

Thanks Rev, I knew I was missing a setting somewhere. I will get better at looking at these logs myself with MLV, I probably could have figured that out if I charted the correct value. Once I get the min/max values set, I will get my Closed-Loop Idle Initial Values table filled out with the appropriate value, and see where that gets me in terms of idle stability. I am thinking of disabling EGO/PID entirely to get my idle VE & Spark Tables tuned, any objections to doing that to stabilize it and minimize the usage of EGO to hide a badly tuned idle?

 

According to megalog viewer I am always in closed loop when this happens, so the A/C settings aren't bumping it out of closed loop causing this. I tried tuning my idle VE table + idle initial value table, my car can adjust for every load except for the A/C compressor kicking on. I set EGO authority to 0% and turned off PID control and this still happens, so it isn't related to that. Changing the A/C setting 'Compressor Delay since last on' to a different setting from 4 seconds, so to 10 seconds, etc, causes the loop to delay to occurring every 10 seconds instead of every 4, so it is definitely the increased load of the compressor causing this somehow. I tried to raise the Idle-Up Duty % to 10%, with no change in behavior. Changing idle up delay/Idle up min RPM up a few hundred RPMs each didn't really help either.

I am kinda stumped here, when I rev the car the A/C cools just fine, with the stock ECU A/C worked perfectly everywhere. Log and updated tune attached, anyone have any ideas?

I am going to see if using spark advance to handle additional loads helps, it looks like my spark retards by 5 or so when the compressor kicks on, I think it should be advancing instead. Not sure why it would go down like that

 

Fixed the A/C at idle issue!

I enabled the Idle Advance Timing Table using DNMAkinsons settings from this thread

I tried to use the Idle RPM Correction Curve Table as well, however with it enabled my car would die shortly after crank. It would probably work if I cranked down my default spark advance values a bit, but I am not going to use it til I get my other values in check. I didn't modify my spark table at all so it is pretty advanced with this table, however the car idles pretty well and doesn't stall with increased electrical loads.

 

Just kidding, it still happens. It was working while I had the car running earlier, with no settings changed at all it started happening again. If I hold the gas pedal to 1.2k rpm or so the ac works and the issue doesn't happen, so that's what I am currently doing. No idea what to try next, here's a datalog of it.

UPDATE - I fixed it for real this time, changing Idle-Up Min RPM from 600 to 350 stopped the infinite loop, now it goes to 500-600 rpm, goes to 1200 rpm, then goes to 850rpm and recovers. I should be able to dial that out with the PID settings. I don't know enough about tunerstudio to know what setting was clashing with what, but now my AC works when idling, so I am happy.

UPDATE 2 - I helped the idle bouncing + idle dip when enabling AC by changing the compressor delay to 750ms, any less and the idle dips substantially. I don't think this is the best way to fix this, but it works for now.

 

The only 'issue' I still have is the reported knock on Cylinder 3 every time I start the car. What are the chances this is falsely reported/caused by an over-active knock sensor? I am wondering if I managed to pinch an O Ring or a gasket isn't seated correctly on the fuel injectors, I will check those when I get my squaretop installed.

Here are my knock settings, its just Revs basemap. Haven't modified them yet.




This happens in almost all of the logs I have uploaded, cylinder 3 knock at 100% the second the engine catches and starts running. I will get a new datalog the next time I start the car showing this. I haven't made any changes in the startup settings yet as it is working well enough.

 

Our knock sensors suck so I wouldn't be concerned or even trust them with my engine. Use a conservative map or tune with det cans.

But since you are not even turbocharged, don't worry about any of it. The only appreciable detonation you will have is once boosted.

 

Ignore startup knock/knock with no load. As the MS3 uses knock windowing, it gathers all the noise during that 30* window - and at very low rpm, 30* is a lot of time to gather noise, which is accumulated and reported, hence the knock signal. Just ignore everything below 1200rpm through the settings.

 

Will do, thanks for the confirmation that it's just an overactive knock sensor. I will look into creating some det cans before I yoink parts of brains base timing map and see how the car likes it.