MSefi.com read only forum (Jan.15,2018)

Cool! I will try and make it as well.

Bill

Well, decided to play aroud with the settings. I set the wide band algorithm to PID/Smith, and left the settings at the default values. Correction surge is gone even with the O2 control set to a higher value! I think my VE table is pretty close, AMC usually only needs to correct 1-2% or so. Also AMC ...

So I have been thinking of a way to try and reduce my O2 correction surge at very light engine loads. Right now I just set the O2 authority very low (2%) to stop it. However I would like to be able to set it a tad higher say 5%. To allow for greater closed loop corrections do to elevation changes ...

20% is high enough where it should be greater that normal TPS noise. Unless you have a worn/bad TPS, that is causing erratic voltage signals. This could "trick" MS into thinking that your moving the throttle more than you really are.
Should show up in the data log, if its causing the problem though ...

Plato2k5

Could be the accel enrich kicking in. This can happen if the Map or TPS threshold is set to low in the accel tuning data. I find it helpful to run a datalog, and set up one of the graphs to read ARF and accel/enrich. Makes it very easy to spot!

Bill

vinister
I am at the same point as you. Take it for a drive, run data logs set to very hard. Sometimes it will want 1% richer, other times it will want 1% leaner or no change. What I do is look at the 02 data, it appears to be pretty darn close. So I just go with the setting that it runs best at ...

Green is lean, red is rich. The switch point is 14.7 to 1 if you have MS set up for gasoline.

Bill

Jim
It's currently at 2.0. If the IAC continues to work correctly, I'll most likely leave it there.

Bill

I set my min step size to 10 last week. So far it's worked correctly every time!

Bill

Jim
Still kinda messing with it. One thing I did notice, if I narrow the spread size between the high and low settings in "other tuning idle steps" it helps a lot.
When I increase the cold fast idle #s, so the cold idle isn't as high, it will work correctly most of the time. I believe it's because ...

Phillip
I increased the step size to 8. It seems to be operating better now. I'll have to do a few more cold starts to be sure. Takes a bit of time, making an adjustment and waiting for the motor to cool all the way down!
Brian
I havn't thought about "shifting the scale" up into 200 range. If it ...

Now that the weather is nicer, it's time to take another crack at tuning my IAC.
What is happening, is the IAC will not close completely from a cold start after the engine is warmed up. After the engine is warm, I can cycle the key off, re-start, Idle speed will then drop down to curb idle ok after ...