Bosch PWM Idle Valve Polarity
Moderators: jsmcortina, muythaibxr
Re: Bosch PWM Idle Valve Polarity
I finally got it working! Abandoned the test setup (ie a 12v source from the battery) and tried using it wired up to the IGN 12v feed I'd originally set up.
Started at 50hz and could hear quite a lot of noise so figured I'm onto something, tried the test mode again and got nothing. But after turning the test mode on and off a couple of times, it sprang to life - only when entering pretty high values though. Settled on 99Hz as that reduced the noise to almost silent but still got the valve moving.
For some reason it seems to want a duty of 60+ to do anything, so the effective range of the valve is basically 60-100. At 67 it's shut, at lower it goes slightly open again (like when off) and at 90-100 it's WIDE open.
I never lingered in this area when testing it before as I hadn't seen anyone else use these values, but it definitely works in test mode, and now that I've fit it into the car, 67 definitely seems to get the lowest idle. Lowest idle is still a bit higher than it was before installing the valve but at least I now have some sort of warmup idle speed control!
Started at 50hz and could hear quite a lot of noise so figured I'm onto something, tried the test mode again and got nothing. But after turning the test mode on and off a couple of times, it sprang to life - only when entering pretty high values though. Settled on 99Hz as that reduced the noise to almost silent but still got the valve moving.
For some reason it seems to want a duty of 60+ to do anything, so the effective range of the valve is basically 60-100. At 67 it's shut, at lower it goes slightly open again (like when off) and at 90-100 it's WIDE open.
I never lingered in this area when testing it before as I hadn't seen anyone else use these values, but it definitely works in test mode, and now that I've fit it into the car, 67 definitely seems to get the lowest idle. Lowest idle is still a bit higher than it was before installing the valve but at least I now have some sort of warmup idle speed control!
Triumph Spitfire 1500 - MS3 + MSX running sequential injection with direct coil control.
Re: Bosch PWM Idle Valve Polarity
Should also add, polarity definitely doesn't matter, I tested this. You can put the 12v feed to either pin (and the MS3X wire to the other) and it will work both ways.
Triumph Spitfire 1500 - MS3 + MSX running sequential injection with direct coil control.
Re: Bosch PWM Idle Valve Polarity
I have been trying to use one of these valves but having real problems. In test mode initially valve will not open until high values are tried and then it will not close even when setting duty to zero. I even bought a second valve but exactly the same issues. Can anyone recomend a 2 (or 3) wire valve to use in PWM that just works?
-
- Site Admin
- Posts: 39619
- Joined: Mon May 03, 2004 1:34 am
- Location: Birmingham, UK
- Contact:
Re: Bosch PWM Idle Valve Polarity
How are you wiring it and what settings. I've used these valves in three different cars and tested on the bench also.
Do note that the diode from signal to 12V is required to give the valve a good operational range.
James
Do note that the diode from signal to 12V is required to give the valve a good operational range.
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
Re: Bosch PWM Idle Valve Polarity
My ECU was supplied by Phil R who tells me the diode is fitted, there are only 2 wires, one to +12V and one to ECU. I have tried all the settings I can think of, idle valve test 0 - 100, please suggest settings.
Re: Bosch PWM Idle Valve Polarity
I fixed my operating range with the diode - didn't realise it was needed on the MS3X output, which is what I'm using.
That kicked the range down from 70-90+% to 30-60%, and made it's operation noticeably smoother.
Even when working well, these valves don't close when the duty is zero. At their lowest setting, the valve is open about 1/4". Then when you add duty, it quickly closes, and then begins to open again at the other side of the stepper thingy. That's where you get the proper operating range.
Before I added the diode, from around 65 up to 70% would get the stepper to start to close from it's default 'slightly open' setting, a few percent after that wouldn't let air out either side, then the gap would open on the other side above about 73%. Does this describe your symptoms? This is at 100hz by the way.
That kicked the range down from 70-90+% to 30-60%, and made it's operation noticeably smoother.
Even when working well, these valves don't close when the duty is zero. At their lowest setting, the valve is open about 1/4". Then when you add duty, it quickly closes, and then begins to open again at the other side of the stepper thingy. That's where you get the proper operating range.
Before I added the diode, from around 65 up to 70% would get the stepper to start to close from it's default 'slightly open' setting, a few percent after that wouldn't let air out either side, then the gap would open on the other side above about 73%. Does this describe your symptoms? This is at 100hz by the way.
Triumph Spitfire 1500 - MS3 + MSX running sequential injection with direct coil control.
-
- Experienced MS/Extra'er
- Posts: 292
- Joined: Tue Jan 01, 2013 3:37 pm
- Location: Dover, MA., USA
Re: Bosch PWM Idle Valve Polarity
I am using one. The valve operates between about 70% and 95% (just closed to full open). From about 15% to 0% duty it opens some again - a sort of failsafe.
I hadnt heard of the diode trick. Makes sense though.
I hadnt heard of the diode trick. Makes sense though.
A2 VW GTI 9A - MS3/3X
Re: Bosch PWM Idle Valve Polarity
Thanks very much for the advice offered, I knew about the intial open position but not sure the advice does cover the symptoms I have, I 'll try again with the settings you recommend and get hold of a diode as well.
25/05 - put a diode in the loom near to the valve this morning and transformed the valve behaviour, controlling nicely now. Thanks to everyone who offered advice.
25/05 - put a diode in the loom near to the valve this morning and transformed the valve behaviour, controlling nicely now. Thanks to everyone who offered advice.
-
- Experienced MS/Extra'er
- Posts: 292
- Joined: Tue Jan 01, 2013 3:37 pm
- Location: Dover, MA., USA
Re: Bosch PWM Idle Valve Polarity
I added the flyback diode today. The operational range went to around 30% closed and 80% open, using the TS idle valve output test and engine RPM as the indicator of open and closed. After adjusting the idle control and cranking PW settings accordingly, I found the engine does indeed start up, gets to idle and maintains idle better.
A2 VW GTI 9A - MS3/3X
Re: Bosch PWM Idle Valve Polarity
can i use this valve like Fidle valve?
-
- Site Admin
- Posts: 39619
- Joined: Mon May 03, 2004 1:34 am
- Location: Birmingham, UK
- Contact:
Re: Bosch PWM Idle Valve Polarity
Do you mean as an on/off idle valve ? They typically flow way too much air and are not designed to be used like that.sober wrote:can i use this valve like Fidle valve?
Use them in PWM mode as they are designed.
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
-
- MS/Extra Newbie
- Posts: 1
- Joined: Tue Feb 23, 2016 10:48 am
Re: Bosch PWM Idle Valve Polarity
Can anyone tell me where to find the 2 pin connector for this ICU?
-
- Experienced MS/Extra'er
- Posts: 338
- Joined: Thu Oct 20, 2016 9:12 pm
- Location: Manassas, Virginia
Re: Bosch PWM Idle Valve Polarity
It's a standard Bosch EV1 style connector.mightywizard wrote:Can anyone tell me where to find the 2 pin connector for this ICU?
GM Style EV1 Rear Insert Connector Kit:
http://www.bmotorsports.com/shop/produc ... cts_id/943
GM Style EV1 Rear Insert Connector Pigtail:
http://www.bmotorsports.com/shop/produc ... cts_id/944
I'm in the VA/DC area! Let me know if I can help you locally! I offer tuning and troubleshooting services.
http://www.msextra.com/forums/viewtopic ... 37&t=64269
Email me directly at CRSTune@gmail.com
Personal Vehicle:
'92 Nissan 240sx, KA24DET, GT2860RS, MS3X, Coil-on-Plug
http://www.msextra.com/forums/viewtopic ... 37&t=64269
Email me directly at CRSTune@gmail.com
Personal Vehicle:
'92 Nissan 240sx, KA24DET, GT2860RS, MS3X, Coil-on-Plug