NB Idle valve issue - PWM valve running DIYPNP MS2 - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 08-28-2013, 09:30 AM   #21
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

I have removed the ECU from the car and put the original ECU back in to test the valve, it appears to be working fine.

Now I am connected to the DIYPNP MS2 via RS232 and have it on a 12V power supply.

When I measure a 12V source on the board it is reading 12.01V on the DMM. When I measure between the IAC output and 12V I get a reading of 10.61V regardless what I set the frequency and PWM % too in TunerStudio. This is also true for when I try and use the Idle Output Test with any settings.

The only way I have been able to get the IAC voltage to change is if I enable the FIDLE output as shown in this screenshot. Something that I think is strange is when you disable the FIDLE output it stays at 12V until you reset the ECU (the same as what it was doing on the car).

Now the ECU is off the car and I am bench testing is there anyway I can test the IAC operation?
Does anyone know what the IAC point on the sequential injector board is for? (I have not connected anything to it)
Is there something stupid I might have done that I can check for?
Attached Thumbnails
NB Idle valve issue - PWM valve running DIYPNP MS2-idle5.jpg  
wydra is offline   Reply With Quote
Old 08-28-2013, 10:05 AM   #22
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

Quote:
Originally Posted by LumptyLump View Post
Does the engine fast-idle for 6 seconds, just as it starts, before dropping? That's what your setup showed in post#11 for crank-to-run time. If it does, then you know your IAC valve operates.

Have you disabled idle control in order to experiment with FIDLE? I see the crank-to-run setting greyed out in post#15. If so, be sure MS is set to operate the IAC normally.
Nope there is no fast idle at all, the valve isn't working at any time.

Yes I have set Idle Control to "None" when I enable FIDLE, it acts the same if I have it set to none or if I still have PWM warmup or PWM closedloop selected.

The crank-to-run gets greyed out when you have PWM closed loop selected because the settings is in the 'Closed Loop Idle PID Settings' window.
The crank-to-run is visible when I select PWM warmup (screenshot below)
Attached Thumbnails
NB Idle valve issue - PWM valve running DIYPNP MS2-idle6.jpg  
wydra is offline   Reply With Quote
Old 08-28-2013, 10:41 AM   #23
Newb
 
Join Date: May 2013
Location: Yes. There really is a Kalamazoo!
Posts: 32
Total Cats: 3
Default

By your description, it sounds as though it might be a hardware problem. I'm afraid I don't have enough experience yet to be of much help. I hope others will chime in.

It's still possible to have overlooked something in the setup though. If you'll post your .msq file, maybe one of us will see something that needs to be changed.
LumptyLump is offline   Reply With Quote
Old 08-28-2013, 10:47 AM   #24
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

Yeah I am pretty confident it is something hardware related.
Here is the .msq that I am currently running.
Attached Files
File Type: msq CurrentTune.msq (84.0 KB, 68 views)
wydra is offline   Reply With Quote
Old 08-29-2013, 08:12 AM   #25
Newb
 
Join Date: May 2013
Location: Yes. There really is a Kalamazoo!
Posts: 32
Total Cats: 3
Default

I don't see anything that could account for the lack of IAC control. Maybe others can see something. Meanwhile, how is the hardware testing coming along? Find anything?
LumptyLump is offline   Reply With Quote
Old 08-29-2013, 09:52 AM   #26
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

Nothing useful unfortunately.

I have found that Pin 20 of the J2 header on the microsquirt module is for FIDLE. This is also giving the 10.61V output, the same that is seen at the IAC pin that goes to the connector board.

Do any MS guys out there know if this behavior is correct?
Does the FIDLE pin out of the ECU connect directly to the IAC pin and works with the PWM valve (with the inclusion of the pull up diode to 12V)?
Is there anything I can be testing to see if the IAC is functioning correctly?
wydra is offline   Reply With Quote
Old 09-01-2013, 11:06 AM   #27
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

So I have been told the hardware is doing what it should be doing and this is probably Software related.
Great, software should be easier to fix fight?
Can anyway shed any light on what might be going on?

I have upgraded firmware to 3.2.5 with the same results.
Not really sure where to go from here.
wydra is offline   Reply With Quote
Old 09-01-2013, 01:39 PM   #28
Senior Member
 
Join Date: Apr 2011
Location: Hollywood, FL
Posts: 523
Total Cats: 18
Default

When I first installed my DIYPNP I had the same issue except mine was an easy fix. I forgot to install the flyback diode. Is yours installed?
hector is offline   Reply With Quote
Old 09-01-2013, 11:24 PM   #29
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

Thanks Hector, I wish it was something like this.
I have the flyback diode installed on R5 (IAC) with the band of the diode going to 12V.
wydra is offline   Reply With Quote
Old 09-05-2013, 07:13 AM   #30
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

I plugged the ECU back into the car to get a log of it trying to control the valve.
I started up the engine and started to log. The valve remained shut and I needed to add accelerator to keep the revs up just as it did before so I stopped the log.
I then turned FIDLE output to 'ON' and the revs shot straight up to 5-6k rpm just as it did before so I switched the engine off.
Then I powered up the ECU again to turn off the FIDLE off and TunerStudio said there was a config error (obviously for having the FIDLE enabled and Idle control on).
I turned FIDLE off and just left PWM Warmup on.

THEN....

When I restarted the engine, the valve is working!
Went into valve test and the valve is following what percentage I set it to with revs increasing and decreasing as I change the figures.

I'm not really sure what is different to before as I have tried this exact procedure with the older 3.2.1 firmware so maybe it is something to do with the new firmware?

Thanks to everyone that tried to help, all is now well
wydra is offline   Reply With Quote
Old 09-05-2013, 08:51 AM   #31
Newb
 
Join Date: May 2013
Location: Yes. There really is a Kalamazoo!
Posts: 32
Total Cats: 3
Default

Good work! I'm glad you've found success!
I'm using an MSPNP2, which is similar, but not quite the same as a DIYPNP, but I suspect they both need to be power-cycled for some changes in setup to take effect. I see a banner appear across the top of my TunerStudio stating such when I enable FIDLE or make other related changes.

I experimented PWM CL idle over the last weekend and I had to power-cycle to get the idle back from 5k or so, when I changed FIDLE or inverted the idle PWM. I also upgraded from 3.2.1 to 3.2.5 and I saw no change in behavior between the two revs in that regard.
LumptyLump is offline   Reply With Quote
Old 09-14-2013, 04:34 PM   #32
Senior Member
iTrader: (1)
 
Join Date: Jan 2012
Location: Tampa, FL
Posts: 761
Total Cats: 19
Default

So, did your idle surge/oscillate?
I'm having this problem right now. Ms2pnp for 99-00 but on my built motor.
My idle test didnt changes anything.
As the car is sitting now if I unplug the iacv the car well keep its idle but oscillates badly. if I keep the valve plugged in it starts,oscillates , and then eventually stalls.
Impuls is offline   Reply With Quote
Old 09-14-2013, 10:43 PM   #33
Newb
 
Join Date: May 2013
Location: Yes. There really is a Kalamazoo!
Posts: 32
Total Cats: 3
Default

I was trying to get a stable idle and still respond to A/C without hunting. I wasn't successful. I could get a stable idle, or I could respond quickly to A/C, but not both.

The MSPNP2 has a trimpot inside to adjust for A/C idle-up. I'll set it up next time I have it out of the car.

I'm not serious about getting it perfect right now anyway. I'm driving the car NA this summer, and will turbo it this fall. I'll need to retune for the turbo anyway and will work out the little details when I have all my new hardware installed.
LumptyLump is offline   Reply With Quote
Old 02-03-2014, 12:03 AM   #34
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

Just for some closure on this topic.
I spent a lot of time getting my PID settings tuned and managed to get the idle 90% there. It would never stall while driving and was quick enough to catch the A/C BUT it would oscillate. At the start the oscillations where quite bad but with some tuning of spark and fuel (had to run it reasonably rich) I got it where it would only oscillate a hundred rpm or so.
The only thing that reduced the oscillation was reducing the frequency multiplier. The suggested is 16x and anything under 13x the valve sounded like a plane propeller so I settled with 13x and dealt with the oscillations for a while.
I then bought a JBPerf PWM converter Board,
PWM Converter Board
set it to 16x and 1x on the MS (and inverted the signal) and now my idle is 100%.

Awesome! I Canít recommend this enough for anyone having issues getting their idle dialled in.
I was even able to lean out the idle A/F to what it should be and it is still rock solid.
wydra is offline   Reply With Quote
Old 02-03-2014, 01:21 AM   #35
Senior Member
iTrader: (1)
 
Join Date: Jan 2012
Location: Tampa, FL
Posts: 761
Total Cats: 19
Default

I idle off of idle screw. Yay me.
Impuls is offline   Reply With Quote
Old 02-03-2014, 08:48 AM   #36
Senior Member
 
Join Date: Apr 2011
Location: Hollywood, FL
Posts: 523
Total Cats: 18
Default

I'm curious as to what you think made it 100%. If I read this correctly you still have the valve at a low frequency 16x. You had it at 13x before so not a drastic change and not really using the function of the board which is to multiply the frequency to one not available in the code.

Which btw, the 3.3.1 code has the capability for much higher frequency. I'm using the 01 TB on my car and running it at 300hz, IIRC. That frequency gets rid of the humming from the valve.

And I don't understand the inverting of the signal?

I'm still nowhere near where I would like to be with my idle but I admit I have not spent any real time tuning it so its my own fault. And part of it may be mechanical issues I am overlooking. But if you think this really did the trick I would be very interested in trying it.
hector is offline   Reply With Quote
Old 02-03-2014, 09:55 AM   #37
Newb
Thread Starter
 
Join Date: Jul 2012
Posts: 20
Total Cats: 0
Default

From everything I read the MS multiplier is a software multiplier and as soon as you start using this you lose resolution (a 10x multiplier only gives 1/10 the steps as a 1x multiplier).

The base frequency of the MS is 30.5Hz so when I ran my 13x multiplier I was running the valve at about 400Hz which was as low as I could get without it sounding too loud.

Now with the board I am running a 16x multiplier on the board and 1x on the MS (multiplying the original 30.5Hz to almost 500Hz) but keeping the full resolution.

This resolution is what has stopped the oscillations.
wydra is offline   Reply With Quote
Old 02-03-2014, 12:39 PM   #38
Senior Member
 
Join Date: Apr 2011
Location: Hollywood, FL
Posts: 523
Total Cats: 18
Default

Got it, thanks for the explanation. I don't have acess to TS right now but I'm positive we have the option of going to 500hz in the 3.3.1 firmware without the need of a multiplier. I wonder if it's the same now as what you have accomplished.

Also you never answered on what you meant by inverting th signal?
hector is offline   Reply With Quote
Old 02-03-2014, 04:20 PM   #39
Junior Member
 
Join Date: Sep 2010
Location: Denmark
Posts: 79
Total Cats: 1
Default

It goes to 480 Hz. The help text reads:

Quote:
Frequency to operate at. This varies with valve type. Ford/Bosch valves typically operate 50-100Hz. Miata valves are closer to 300Hz.
Be aware that above 78Hz the output becomes less precise.
I run mine at 279 Hz.

- Tom
one-niner is offline   Reply With Quote
Old 02-03-2014, 05:18 PM   #40
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

Tom, IIRC your ECU has the expansion board that already does the hardware multiplication.

If you switch to 1x and the valve doesn't buzz, then you have the hw multiplier and in this case, increasing the software multiplier makes it worse.
Reverant is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
mslabs MS2 - Idle control issue ndragun MEGAsquirt 0 09-20-2015 11:28 PM
DIYPNP Won't Stay Running huesmann MEGAsquirt 19 09-16-2015 08:11 PM
Mystery Engine Trouble. Halp, mt.net! vehicular General Miata Chat 12 09-14-2015 04:17 PM
VE values too low? compuw22c MEGAsquirt 4 09-12-2015 08:42 PM
Help Rough Idle Backwoodsballer General Miata Chat 0 09-04-2015 07:39 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:51 AM.