LukaMiataITB

Hi guys...so here is the short drive video...some testing after few mods.


And now my question.
I have an annoying warm idle problem. The car is with itb, cams, ms3 mini...idle valve is removed. Cold idle is good, around 1050 rpm, warmed idle is also good around 1250 rpm.
Problems start when my IAT goes over 35 degrees C, in other words when its heat soaked (sensor is mounted on itb backplate). So after driving and turning the car off under bonnet temp rises to almost 45 degrees....and when I start the car then idle is 1500 or 1600 rpm.
I looked at all possible corrections and I don't know what could cause this. Throttle plates are completely closed, and cold idle is spot on. Or can tuner studio pull some timing depending on iat ?
I would be happy if I could lower it to at least 1350 when its heat soaked.
My tune is on the bottom

thnx

yossi126

iTrader: (6)

How do you expect to have a good idle if you removed the idle valve?
Not trying to be a dick but there's a simple answer to your question.

LukaMiataITB

Idle is good.....my question is why it jumps 300 rpm when iat goes over 35 degress ?

yossi126

iTrader: (6)

If you had a valve you could have contained the heat soak situtation in the tune.

LukaMiataITB

so in short not possible without the idle valve?
well I guess I need an airbox with cold air intake

curly

iTrader: (25)

There's still a lot you can do with your tune, even without an IACV. Remember that increasing timing slightly will slightly raise your idle, and decreasing it will slightly lower it. Now look at your main ignition table. Knowing what I just told you, it's pretty fucked up. The lower you go in RPM, the lower the timing, so if the RPMs begin to fall, it'll want to continue to draw them down. If your idle is 1050, try setting timing to 16ish degrees, and a few hundred RPMs below that, make it 18 for example. Edit: Ah, I see you've already kind of done that. Try a smaller jump, instead of 10 to 18, do the 16 to 18 like I said. And get rid of the 4 degree bullshit, like I said that'll draw the RPMs down, so it may be messing with your tip in to drop so low. Also, if you would like to idle at 1050, it really bugs me that you don't have a 1050 column in your timing or fuel table. Fix that.

Once you fix that, you can set your RPM timing correction curve to really stabilize your idle. I like -10 degrees 100rpm above target idle, and +10 100 rpm below target. This makes ignition timing swing all over the place, but gives you a really stable idle. Only turn this on once you've got a fairly stable idle.

You also have the base map settings for the air density table. In theory this table is correct, however in reality, it leans your **** out. Currently you have 10% less fuel at 45C than at 15C. Take everything that's under 100% and set it to 100% and retune.

your idle ve map has nothing to do with your fuel table, as far as I can see. I'd turn idle VE off and fine tune your fuel table. Otherwise you'll have issues when jumping between the two. When you're ready for more resolution in your idle area, set the entire idle VE table to the same as the idle region in your main fuel map and tune the idle VE to perfect the idle.

Basically, your tune is **** and could use a lot of help. Hope that helps.

LukaMiataITB

Thnx curly i will try some of that
So how much timing should i set where i have 4 degrees now?

And other question...I'm still running semi-sequential injection, everything is already prewired for sequential.....so i only need to connect two wires.
If i do that and set the injection to sequential, how much do I need to change in the tune?
And is it worth it at all?

LukaMiataITB

So i noticed two more things
When the sensor is really heat soaked (40 degrees c) car is running more rich....around 11.5.
So I'm guessing I don't need to touch mat corrections ?
And after everything is heat soaked tps is showing 1% and that is also one of the reasons for higher warm idle.
I'm guessing butterflys are expanding a little from temperature and turning the tps just slightly. When the car is cooled down tps shows 0% as it should be

Ted75zcar

iTrader: (2)

Not feeling particularaly verbose right now, but here is some data and a couple high level observations

- You can select the target idle RPM by targeting idle MAP, idle SPARK or (not shown) nominal idle IAC PWM. You can then configure the idle timing correction curve to provide the level of correction you desire
- A cold engine requires more torque (load) to maintain a specific RPM than a hot engine
- Notice that the required load actually increases with a decrease in RPM, I theorize that this is due to a reduction in burn efficiency coupled with an inflection associated with overcoming parasitic loss. This inflection occurs around 1000 RPM on my setup, and surprize, pretty much everybody takes the easy way out and idles at 1000

LukaMiataITB

so here is the last idle log....cold start, then i left the car so everything can get little heat soaked and then the warm start. Maybe you guys can see something from this.

Ted75zcar

iTrader: (2)

Post screenshots of the areas of interest as well, I rarely browse the forum from a PC and simply don't have time to open logs from the forum very often.

LukaMiataITB

Yeah log is too big....but I looked at it everthing looks more or less ok.

Guys thnx so far...I will continue tomorrow with testing