MS2 PWM IAC (01+ 2G & SRT) Settings?

dawm · Post by **dawm** » Fri May 07, 2010 5:17 pm

Finally got the car to not die immediately after starting, but now i can only get it to run by playing with the pedal since the PWM IAC settings i have wants to keep the car at 3500+rpms (tried changing some values in the duty table with no luck)

anyone got some good setttings for MS2 w/ the SRT IAC?

dawm · Post by **dawm** » Wed May 19, 2010 7:17 pm

Ok so no SRT settings, how about settings for the regular 2g PWM IAC ?

please dont make me have to use this ford iac valve..

ZeroChad · Post by **ZeroChad** » Wed May 19, 2010 9:10 pm

I'm actually wondering about this right now as well.

Jamie · Post by **Jamie** » Wed May 19, 2010 10:48 pm

I know I had my settings for my valve inverted by accident and it reved and held at about 3500-4k. I would make sure that your initial settings are correct first, then go about tuning it. Idlevalve test function is the sh!t.

dawm · Post by **dawm** » Sat May 22, 2010 3:50 pm

Jamie wrote:I know I had my settings for my valve inverted by accident and it reved and held at about 3500-4k. I would make sure that your initial settings are correct first, then go about tuning it. Idlevalve test function is the sh!t.

any chance you'd share your settings?

Jamie · Post by **Jamie** » Sat May 22, 2010 9:49 pm

They are on my laptop. next time Ill fire it up ill take a look at my msq. Mine are a rough setting and not quite right. other irons in the fire so havent had time to run it. but its getting close. when I get a chance Ill let you know.

Jamie · Post by **Jamie** » Thu May 27, 2010 11:31 am

Does an SRT use a 4 wire idle control valve? anyhow these are my settings. use them with FULL WARNING THAT THESE WORK FOR ME AND MAY OR MAY NOT WORK FOR YOU. I AM NOT RESPONSIBLE FOR ISSUES THAT MAY ARRISE FROM USING MY SETTINGS!

phew okay now that that is out of the way, these are my settings that I am using now. it idles pretty good but it isnt perfect. there are lots of variables at work at the same time so make sure your ve table and timing table are right or else changes in these will throw your idle off.

ok, under IDLE CONTROL
Algorithm : IAC cloased loop always on
time step size 2.6
minimum #steps to move(steps): 1
Start value 160

COOLANT BASED CRANK STEPS
50.0f 20steps
100f 27steps
150 21
210 31

CLOSED LOOP IDLE VALVE SETTINGS
idle open steps 255
Idle valve closed steps 0
Idle activation rpm adder 50
Idle activation tps threshold 2.5
Dashpot adder 15
Close delay 2

CLOSED LOOP IDLE PID SETTINGS
min steps for PID 5
RPM with valve closed 400
RPM with valve open 1400
PID delay 1
Crank to run taper 5
PID ramp to target time 2
PID control interval 100
Proportional gain 35
Indegral gain 50
Derivitive gain 0
PID lockout rpmDOT threshold 50
PID lockout max decel load 25
PID disable RPMDOT 100

dawm · Post by **dawm** » Thu May 27, 2010 12:35 pm

the srt and 01 through 05 neon use a 2wire pwm iac

your iac must be a 4wire stepper so those settings will work for 1g's and 00's with the stepper iac.

thanks for the info tho, might help someone using the stepper iac but not the pwm iac.

Post by **occasional demons** » Thu May 27, 2010 12:46 pm

pwm = pulse width modulated? I assumed they just varied the voltage. Didn't put too much thought into how, but doing it by pulse width makes sense. Cool I semi-learned something. The day is not a total loss.

Jamie · Post by **Jamie** » Thu May 27, 2010 1:47 pm

yup, pwm = pulse width modulation. I didn't think they used the 4 wire stepper but I have been proven wrong before.

Post by **occasional demons** » Thu May 27, 2010 2:44 pm

'00 is the only year 2gn's used the stepper, unless there were some early '01's that got some. I doubt it, by reasoning of keeping x amount for parts sales. Far more profitable.

I suppose you could think of the '01-'05 IAC as a huge fuel injector. Except air is the metered medium, and the pressure difference is the pump.

esteinmaier · Post by **esteinmaier** » Thu May 27, 2010 3:40 pm

I find it more manageable to either use the stock IAC and put up with a slightly surging idle or crack the TB open a little bit. It seems like everyone has problems with PWM IAC on MS, so I'm planning on doing ASP manual IACs with a cold valve in addition to the main valve. So you cold start it and let it warm up with both valves open, and then once it gets warmer, close the secondary from within the car to get a lower idle. (Otherwise your idle creeps up as it gets warmer.)

dawm · Post by **dawm** » Thu May 27, 2010 3:50 pm

esteinmaier wrote:I find it more manageable to either use the stock IAC and put up with a slightly surging idle or crack the TB open a little bit. It seems like everyone has problems with PWM IAC on MS, so I'm planning on doing ASP manual IACs with a cold valve in addition to the main valve. So you cold start it and let it warm up with both valves open, and then once it gets warmer, close the secondary from within the car to get a lower idle. (Otherwise your idle creeps up as it gets warmer.)

So Erik, any chance you have some PWM settings for the stock IAC to share? I know Grrrtrude (did i add enough r's?) is at least an 03.

ZeroChad · Post by **ZeroChad** » Fri Jul 30, 2010 12:17 am

So here are my settings for pwm warmup. I'm thinking on saturday I'll give PID control a shot. I have it setup so that its always 'warming up'. It works pretty stable, but not perfectly (PID will be better). You'll need the warmup enrichment points set as far left as the pwm table goes. aka set a point to 100% at 222F.

ZeroChad · Post by **ZeroChad** » Wed Aug 04, 2010 12:47 am

Sweet. Tomorrow, I'm double checking my settings to make sure its running good. I'm pretty impressed by the ability to let the PS kick in and the PID algorithm compensates quickly.

Dang, this section has been dead lately.

dawm · Post by **dawm** » Wed Aug 04, 2010 5:35 am

awesome, thnx please post the PID settings when you got em fugured out

ZeroChad · Post by **ZeroChad** » Mon Aug 09, 2010 12:40 am

So these settings appear to be pretty stable. I finally figured out why it was oscillating. It was due to the my ignition advance column at 1100 rpm.

Here's my PID settings:

dawm · Post by **dawm** » Tue Aug 10, 2010 7:26 pm

Thanks!, hopefully i will close on my house and finally have my car 'right outside' instead of 'across town' so i can play with these settings.

can you post the #s for the PID grapht? (click the ... button in the upper right of that graph, then take the sshot) I hate 'guessing' at graphs

ZeroChad · Post by **ZeroChad** » Tue Aug 10, 2010 7:53 pm

There you go. I'm trying PID values of 100/45/5 today as well. I think I'm getting a little less oscillation. Now that ignition advance isn't factoring into it, it's a little easier to dial in. I imagine you'll need to play around with them a little bit for what's best on your engine.

dawm · Post by **dawm** » Tue Sep 21, 2010 8:24 pm

I'm finally moving the car (hiring a flatbed) over to the new house Thursday. I'll try out these settings this weekend

dawm · Post by **dawm** » Wed Sep 29, 2010 10:35 pm

TunerStudio wont let me set Closed loop Idle PID Settings-> PID ramp to target (sec)' to 0 as you have in your sshot, it says the lowest setting is 2.

But i will be testing your settings out tomorrow ;D my car is finally just a few steps out my back door instead of all the way across town

ZeroChad · Post by **ZeroChad** » Thu Sep 30, 2010 12:41 am

Huh, that's odd. I don't think I even touched that setting from default.

dawm · Post by **dawm** » Thu Sep 30, 2010 7:01 pm

tried out the settings and their better than what i had for warmup only, i still have to play with the throttle to stay running until it warms up but then its a pretty smooth 700-800 idle but after a few seconds it goes all wonky and the idle range goes from 500-900 alternating and it usually stalls out. i really need to find someone local to take a look at my setup and help me get it tuned, but im gonna have to wait until i swap out my junk clutchnet clutch (brand new too) and toss in the clutchmasters stage 4 clutch before its able to see the road.. (unable shift gears while the engine is running due to the junk clutchnet clutch)

ZeroChad · Post by **ZeroChad** » Thu Sep 30, 2010 7:22 pm

You can try messing with the PID values to get rid of the oscillation. Reading the PID wiki will give you a little clue on what they do for feedback control.

dawm · Post by **dawm** » Sun Oct 03, 2010 5:17 pm

what wiki do you speak of? i cant find a megasquirt one

ZeroChad · Post by **ZeroChad** » Sun Oct 17, 2010 6:08 pm

So I upped the pwm lockout detection field and that helped drastically reduce any surgin/oscillation that develop during warmup. I think its at about 1000 now. My issue was that it would get rise and then fall due to overrun cutoff and stop adjusting due to the rate of rpm change.

ZeroChad · Post by **ZeroChad** » Fri Oct 22, 2010 12:53 pm

http://bit.ly/9yBec5
This helps understand the parameters so much! I don't know why it wasn't in the MS2 documentation.

I'll post my new settings soon. things are becoming extremely stable.

anomalous0 · Post by **anomalous0** » Wed Feb 09, 2011 3:57 am

I know this is something of a post resurrection, but I happen to have a multimeter that lets me measure frequency and duty cycle, and on an 02 neon, the PWM IAC runs at about 76hz, (which translates to a valve frequency of 2.5), at about 20% duty cycle on a cold engine (outside temps of about 50F). Just throwing it out there to see if it might be handy to know the stock parameters.

dawm · Post by **dawm** » Fri Feb 11, 2011 6:46 pm

ZeroChad wrote:http://bit.ly/9yBec5
This helps understand the parameters so much! I don't know why it wasn't in the MS2 documentation.

I'll post my new settings soon. things are becoming extremely stable.

post em

im still using the old ones you posted (altho i just started the car today. last time was prolly in august

) hard to start but eventually got it going, it eventually idled but horribly rich, i didnt have my laptop hooked up or anything so i have no idea what rpm it ended up at (tach still isnt working) was just starting her up so she didnt get all cranky and rust up.

hopefully when warmer weather hits ill be dropping the trans and putting in the CM Stage 4 clutch and maybe it will shift again and ill be able to start playing with tuning again.

dawm · Post by **dawm** » Tue May 03, 2011 10:20 am

ZeroChad, still around?