ConnorRigby

I'm having a REALLY hard time understanding the parameters that trigger closed loop idle mode.
For starters, my TPS is broken. here's a thread about that :( i know fixing that would probably help with this issue, but i still don't believe what is happening to me should be happening.

I've attached a log and my current tune. Basically while cruising at 2-3k RPM, my car enters closed loop idle mode (???). I've looked at the parameters and from what i understand it goes something like this:

1) TPS < 2% (always true, TPS doesn't really work)
2) RPMdot is < 80% (i assume this is that the engine is decreasing in rpm at 80 rpm/sec, tho i'm not 100% sure about that)
3) when the RPMdot threshold is met, load must be below 28%

as far as i can tell by looking at the logs, the only parameter my engine meets is the first, tho while cruising my closed-loop is triggering. What i don't understand is what:
Leave valve closed above:(rpm)
is for. As while cruising, i would expect that the valve should not be open above this RPM, but there it is, openinig.

Any help would be appreciated.

Davezorz

iTrader: (2)

RPM dot is you instantaneous change in RPM. whenever the RPM is changing less than 80 RPM per second, this criteria is going to be met, Most of your log you are under this threshold. This makes for 2 of the three criteria to enter closed loop. look at the long cruise in the log from 68 to 85 seconds, you spend most of your time here under 80 RPMDOT.

your understanding of MAX decel load is backwards, the car enters closed loop when the map reading is above the value you enter here. This is to prevent you from entering closed loop when you are engine braking down a hill. I can see in your log you are coasting down hill in a gear at about 46 seconds, see how your map drops to 19.9? you would want the value to be above 19.9, but below your normal idle kpa which seems to be around 33.4. Since you are always above 28 KPA in your log, when the other criteria are activated, you enter closed loop idle.

you really need to get your tps fixed, right now the only thing that is keeping you out of closed loop idle is RPMDOT. both of the other criteria are almost always met, as soon as your rpm settles below 80 rpm/sec, you enter closed loop regardless of what the motor is actually doing.

bmxfuel007

iTrader: (21)

TPS is pretty important for closed loop. It's funny because when my tps wasn't working correctly (randomly registering throttle during startup when warm), my car wouldn't enter into the closed loop idle settings. Something as simple as 3 or 4 percent TPS was preventing me from idling correctly, especially since I was using my idle VE table.

ConnorRigby

Yeah i've got a more reliable TPS setup working now which has more or less fixed this issue. I still have some nerd gripes tho.

I modified the latest mega squirt source code (v1.4.0 really megasquirt???) release to check for target rpm instead of tps and my particular closed loop idle was way better. (obviously do to my TPS not being ideal)


i basically changed that to check if RPM was higher than the target idle rpm + some grace and it worked flawlessly. Unfortunately that release is from 2014 and other things ran bad so i opted just to fix my TPS instead.
Does anyone know when/if MS plans on releasing the source of 1.5.X firmware?

ConnorRigby

Welp i finally got my TPS working and now CL idle works right. Thanks for the help everyone