Closed loop IAC control documentation

This is a forum for discussing the development and testing of alpha MS2/Extra code. Documentation
(Runs on MS2 and Microsquirt)

Moderators: jsmcortina, muythaibxr

UnaClocker
Super MS/Extra'er
Posts: 1933
Joined: Fri May 07, 2004 12:59 pm
Location: Tacoma, WA
Contact:

Post by UnaClocker »

Asteris wrote:After jumpering the two big resistors, problem is solved.

So, if now a coil blows inside the stepper motor, IAC controller will short circuit and goes bang, right?
The jumper around it suggestion came straight from Al Grippo.. But if you're really THAT concerned you could put a fuse inline to each coil. Heck, come to think of it, the MS is supposed to have a 1 or 2 amp fuse on it's main power feed. That should be small enough to keep from blowing that IAC controller.
Brian
'84 Dodge Rampage
Asteris
Helpful MS/Extra'er
Posts: 146
Joined: Sun Nov 13, 2005 2:40 am

Post by Asteris »

Asteris wrote:Small remark. When Idle set at Closed loop IAC, cranking position steps are Grey. Motor goes to the value taken from PWM cranking position (you can change that if you select PWM closed-loop), but it allows only 1-100 values, where stepper motor may need higher value.

Also Idle Valve closed Duty or Steps (%), doesn't affect operation, motor moves between Idle Open Duty or Steps (%) and Min Duty or Max Steps for PID (%).
As i remarked before, no cranking IAC step available when at closed loop IAC. Had to tweek ini file, because revs were up to 2500 for a couple of seconds.
offtrack
Helpful MS/Extra'er
Posts: 65
Joined: Wed Jan 09, 2008 6:41 pm
Location: Puget sound, and Peru. yah 2 homes.
Contact:

closed loop idle control

Post by offtrack »

got beta 19 loaded.

I have a 2 wire, fast pintle idle controller valve on my engine.
has 5ms total closed,open, closed time. (have scope photos)
which of the below should I try this valve after warmup and to
hold idle , regulation under most loads.

IDLE CONTROL tab: MT:

PWM closed loop ?

IAC closed loop moving only?

IAC closed loop always on.?

or , Not coded yet?

this should get me going so I can try it.

If I had a stepper , id throw it away and put in one of these.
the only way to go, IMHO.

thanks for any help.
MS2V3+msextra,beta21+
DiyAutotune! < the best!
custom pnp harness done, default timings.
idles, cool, tripadation sets in, MLV soon.
2 years till retirement, then doing MS on wifes family cars. for economy $7 gallon fuel.
muythaibxr
Site Admin
Posts: 8228
Joined: Thu Oct 14, 2004 12:48 pm

Post by muythaibxr »

Depends... if your valve is a stepper motor (usually 4 or 6 wires) then you want IAC always on or IAC moving only (closed loop).

If you have a 2 or 3 wire PWM valve, you'll want PWM closed loop, but if it's 3 wires, you'll have to build a circuit to control it.

Ken
offtrack
Helpful MS/Extra'er
Posts: 65
Joined: Wed Jan 09, 2008 6:41 pm
Location: Puget sound, and Peru. yah 2 homes.
Contact:

simple..

Post by offtrack »

i have ( blessing )a simple and lightning fast , IAC solenoid Pintle air valve.
my stock car ECU toggles it in under 5 miliseconds, end to end.
it is PWM by the stock ECU.
I desire to have this same control.

2 wire ( a single winding on coil) ( have TIP122 driving it with Flyback on unit)
fast
solenoid , not a stepper motor of anykind, (89-95 typical of G16B )


what is the best menu choics on MT?
with this hardware.
thanks for helping, !!!
MS2V3+msextra,beta21+
DiyAutotune! < the best!
custom pnp harness done, default timings.
idles, cool, tripadation sets in, MLV soon.
2 years till retirement, then doing MS on wifes family cars. for economy $7 gallon fuel.
muythaibxr
Site Admin
Posts: 8228
Joined: Thu Oct 14, 2004 12:48 pm

Post by muythaibxr »

With this valve you want PWM closed loop.

You'll also want to read through the various threads to figure out how to tune the closed-loop algorithm.

Ken
offtrack
Helpful MS/Extra'er
Posts: 65
Joined: Wed Jan 09, 2008 6:41 pm
Location: Puget sound, and Peru. yah 2 homes.
Contact:

thanks ! Ken

Post by offtrack »

THANK YOU, Ken.

here is my stock Air valve on scope. ( ECT forced to 32deg F)

it is fast , as lightning.

huh ?

5v/div vert
1ms/div horz.

if someone wanted a fast idle, there are lots of suzuks in the yards
with dead engines.

just cut a plate for plenum end and put on a cheap brass hose nipple.

mine even modulates during cranking! (stock ecu)

hope this helps others too.

Cheers.
MS2V3+msextra,beta21+
DiyAutotune! < the best!
custom pnp harness done, default timings.
idles, cool, tripadation sets in, MLV soon.
2 years till retirement, then doing MS on wifes family cars. for economy $7 gallon fuel.
Post Reply