IAC Closed Loop Question

[turbo conversion]

One more time.

David

[ironwill11]

One more time.

David

Well it seems that I have a particularly temperamental engine that does not want to be tuned. It had a hard time getting up to warm up temp. When it got close, it would start to hunt (same cyclic hunt as before). It was fine until it got down to around 800 rpm. Interestingly enough, the hunt straightens out when put into gear and taken out of gear, it is just there when it is in trying to idle in neutral with no load.

I also noticed in the log that when coming out of drive and going into neutral it is CL idle correction is high, and also CL target idle is higher, as if there is a slope that it is supposed to follow. Is there a way to adjust this slope and make it steeper?

I did notice that while shifting from drive to neutral sometimes the CL idle light would go out and then come back on.

It seems like the it does not like there is no balance for the P and I terms.

This is the datalog:

2017-06-27_20.50.28_hunt.msl

Also did a datalog when the hunt first started during the warm up. It seems like it was using the CL target idle to straighten out the hunt (it would increase the CL target idle to get the hunt to stop, then bring it down again). Could this suggest a problem with my IACV?

2017-06-27_20.48.15_warmup_hunt.msl

Will

[turbo conversion]

One more time.

David

[ironwill11]

TS showed that the difference was in the rpmdot. It does seem like it reacts much better going into drive with the increased load and decreased rpm (could be my imagination and desire). Seems like it does this better then going out of gear into neutral (increased rpms and decreased load). The cyclic oscillation happens around 700 rpm. I have been searching over the internet on some of these terms (CL loop terms) and I can only find megasquirt posts on them. I was looking for some more information to try to gain a better knowledge of what each one does with some examples. Is this something one can only learn by doing/experimenting with the values?

This is my shifting in and out of gear:

2017-06-28_21.15.58_shifting.msl

This is the oscillation that occurred toward the end of warm up:

2017-06-28_21.13.44_oscilation.msl

Will

[turbo conversion]

One more time.

David

[ironwill11]

So I ran that MSQ; It does not show the changes if you open TS and then load a new tune. The cyclic idle is less and at a lower rpm as can be seen in the 600_osc datalog (just showing the oscillation). I also datalogged the gear shifting again. I don't understand why the rpm increases and then PID is recognized, then the rpm is increased further, and then brought down to target idle. Aside from this being strange it makes it difficult to shift from reverse to drive and back and forth, because the idle is high by the time it goes into reverse and then the drive line snaps (K-turns are quite interesting).

The gear shifting log:

2017-06-29_shifting.msl

The oscillation log:

2017-06-29_18.16.49_600_osc.msl

After running these tests I made some adjustments with the P and I terms to try and follow the manual again. I also tried adjusting the PID delay lower but the software does not allow for anything less then 2 seconds. I am just trying to read more, understand more, and try things.

Will