Cold start - RPMs drop at throttle input
 

I have this issue when after cranking, the car is in normal warmup mode until I apply throttle, at which point the rpms drop to "hot" idle area (900-1000 rpm).
I did autotune warmup fwiw.
I have attached a log and msq.

Help would be appreciated.

tune your throttle enrichments; add in some mapdot.

Thanks Scott. I have tried several base maps by you and diyautotune. as I have no idea what I'm doing there. I tried upping the TPSdot considerably but it didn't seem to affect the rpm drop.
Tried time based and accel pump, still no luck.

You've got a pocket of advance at the 30 kPa / 1500 RPM region that is holding the idle high. When you tapped the throttle, it ended up in a load cell with less timing, causing the RPM to drop. Flattening out the spark table in that range should help.

Solved it.
Switched to "last known good idle value".
Reason I didn't use it before is because I didn't figure out it works as the initial table so the max duty was at 80% and the idle got stuck at 3000 rpm.
Anyways, set min to 28~ and max at 40.
Still needs refinement but idle, cranking, coming to a stop etc is much more civilized now.

Band-aid-ed it (which is an OK interim fix, mind you). Last Know will also get you into trouble, as well as out of it. Best to actually get the Initial Values Table set up correctly.

Your Minimum Control setting on your Idle Valve is 32.1. If you set it correctly, that means 32.1 is fully closed and minimum air to engine. Yet, your Initial Value Table (IVT) has lots of values less than 32.

You must find the actual idle values used under the various conditions of CLT(which equals target RPM) and MAT. Then put those values in your IVT.


https://cimg8.ibsrv.net/gimg/www.mia...390ee6cb0e.jpg

EDIT: Wait, did you arbitrarily set your Idle Valve % to 28 and 40? NO. There is a procedure for setting those numbers. They have real meaning, as I described above relating to the 32.1 number.

Read the Setting Up Manual for your MS. It will step you through.

Thanks for your feedback. I read some of your older posts and they have been helpful.
Now the thing gets stuck between 1800-2200 rpm. Is this a bug with "last known good"?
I might as well retry initial duty but clt-based now.

To my (moderately informed) eyes your initial value table looks bass-ackwards. (Correct me if I'm wrong, but) don't you want bigger initial values on the left side of the table and smaller ones on the right side? And, shouldn't the values in the column for your desired target RPM be at, or near the "Closed" valve setting - maybe a little higher for cooler temps, but relatively close? My IVT table looks like this, and it works well for me (my close setting is 27.4);
https://cimg3.ibsrv.net/gimg/www.mia...792fc8c26c.png
PS - my IVT is based on MAT instead of CLT. I've found this to be more sensitive to changing conditions - and a bit trickier to get right - but when it is right, it works well. YMMV

As DNMakinson says, using Last Known Good is a band-aid at best. Getting a good IVT is golden.

I think what got my head scratching for a year now is that my tune is celsius-based while you guys use F. Everytime I tried copying someone else's table I failed miserably.
Will try after work with temperatures adjusted. Thanks.

Yes, that is what I have seen happen in the past.

CLT based table is OK, but MAT works even better. Again, the CLT is captured by the RPM target already.

And Double Again, you must start by correctly calibrating your Idle Valve Min and Max.

When you do look for values from logs, I suggest that you have lights and heater fan on high, and use those values. If you set with electrical loads off, then you may not catch well (of course, Dashpot enters in). If you set with electrical loads on, then you will catch at a little higher RPM when they are off... not a big deal.