Using MS2 V3 with 2.850 beta code.
My Bosch 2 wire PWM is fully closed at a duty cyle of 6% and fully open at duty cycle of 0%. Is this normal as it seems to be a very compressed range and gives very little control of idle speed. I have tried it at 40Hz through to 80Hz and the results are quite consistent.
I also noticed that duty cycle seems to be reversed to what I would expect. 100% being mostly off and 0% mostly on. Any inspiration would be appreciated.
Jon
Help with Bosch 2 wire PWN idle valve
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
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FixItAgainTony
- Helpful Squirter
- Posts: 82
- Joined: Thu Feb 03, 2005 1:09 pm
Hello Jon,
I used a two wire VDO - It may be similar to yours. It has a plunger that moves against a spring. No power = closed which is how I wanted it for failover. There is another style that has a rotating vane in it. I have seen these as a 3 wire set up, but not as a two wire set up. Do you have a picture of your unit?
Notes on mine are below
Charles.
Higher current drive for the PWM Idle driver and V2 flyback diode circuit (TIP120 with a 0.3 ohm current limit transistor). This works on the bench nicely with the VDO 408.202/008/001 PWM idle air valve that I pulled from a SAAB. That unit requires about 1.35A to close. Control range on the idle PWM MegaTune display:
90% starts to open 50% effectively open, 30% completely open. I have not installed the valve in the car yet.
I used a two wire VDO - It may be similar to yours. It has a plunger that moves against a spring. No power = closed which is how I wanted it for failover. There is another style that has a rotating vane in it. I have seen these as a 3 wire set up, but not as a two wire set up. Do you have a picture of your unit?
Notes on mine are below
Charles.
Higher current drive for the PWM Idle driver and V2 flyback diode circuit (TIP120 with a 0.3 ohm current limit transistor). This works on the bench nicely with the VDO 408.202/008/001 PWM idle air valve that I pulled from a SAAB. That unit requires about 1.35A to close. Control range on the idle PWM MegaTune display:
90% starts to open 50% effectively open, 30% completely open. I have not installed the valve in the car yet.
Fiat - A great car for those who like to walk.
-
FixItAgainTony
- Helpful Squirter
- Posts: 82
- Joined: Thu Feb 03, 2005 1:09 pm
Hello Jon,
Nice find on the catalog. I was going to send you a picture, but you got there first. Mine looks very much like:
408-202-008-008G
I was going to try and find yours at the junk yard this weekend. I think the rotary ones work better (quieter) but I have never played with it. I have yet to instal what I have. The PW frequency probably makes a big difference on the noise - I have not played with it recently but will look this weekend and let you know what I find.
Charles.
Nice find on the catalog. I was going to send you a picture, but you got there first. Mine looks very much like:
408-202-008-008G
I was going to try and find yours at the junk yard this weekend. I think the rotary ones work better (quieter) but I have never played with it. I have yet to instal what I have. The PW frequency probably makes a big difference on the noise - I have not played with it recently but will look this weekend and let you know what I find.
Charles.
Fiat - A great car for those who like to walk.
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FixItAgainTony
- Helpful Squirter
- Posts: 82
- Joined: Thu Feb 03, 2005 1:09 pm
pbknowles,
If it were mine, I'd probably put in a current limiting resistor.
I just measured the resistance = 4.0 ohms (measured with meter - no loads).
V= IR; I = V/R = 13.5/4 = 3.4A
I have a note that I wrote on my unit that indicates full DC current at 13.2V was measured to be 2.8A => R = 4.7 ohms, in the ball park with the meter measurement. Call it 3 Amps. Power disappated in the coil winding will be P = VI = 13.5*3 = 40W. Sounds like a lot of heat to me, but less than a head light. I am not sure what they are rated to, but I'd probably put a current limiting resistor in there. It would allow you to adjust the air flow (less current, less air) and it would keep the coil from getting too hot.
The solenoid winding may be (and probably was) designed for full current - think about a really cold climate, duty cycle would be 100% for extended period. Worst case scenario if you run with out the resistor is that the coil will get hot and the winding will open. The valve will close and you will not have any more idle control.
You might see if you can get a data sheet on this or any similar valve and see what the spec it for. If it is good for continuous use you will have no problem.
I will redo my measurements on mine. I think it should have been 1.35A to fully open => You would probably want a ~5 ohm power resistor in there. Let break out the Stim card and MS-II.... I also want to look at frequency effects on the noise this valve makes.
Charles.
If it were mine, I'd probably put in a current limiting resistor.
I just measured the resistance = 4.0 ohms (measured with meter - no loads).
V= IR; I = V/R = 13.5/4 = 3.4A
I have a note that I wrote on my unit that indicates full DC current at 13.2V was measured to be 2.8A => R = 4.7 ohms, in the ball park with the meter measurement. Call it 3 Amps. Power disappated in the coil winding will be P = VI = 13.5*3 = 40W. Sounds like a lot of heat to me, but less than a head light. I am not sure what they are rated to, but I'd probably put a current limiting resistor in there. It would allow you to adjust the air flow (less current, less air) and it would keep the coil from getting too hot.
The solenoid winding may be (and probably was) designed for full current - think about a really cold climate, duty cycle would be 100% for extended period. Worst case scenario if you run with out the resistor is that the coil will get hot and the winding will open. The valve will close and you will not have any more idle control.
You might see if you can get a data sheet on this or any similar valve and see what the spec it for. If it is good for continuous use you will have no problem.
I will redo my measurements on mine. I think it should have been 1.35A to fully open => You would probably want a ~5 ohm power resistor in there. Let break out the Stim card and MS-II.... I also want to look at frequency effects on the noise this valve makes.
Charles.
Fiat - A great car for those who like to walk.
-
FixItAgainTony
- Helpful Squirter
- Posts: 82
- Joined: Thu Feb 03, 2005 1:09 pm
Jon,
I looked at the valve a little more on the bench set up:
MS-11 V3 board, V2 idle air control fly-back installed
Code 2.68
Power source (11 'C' NiMh batteries that I use on my bicycle light - getting a little old...)
VDO 408.202/008/001 2 wire Idle control valve
Settings for PWM frequency = 80 Hz * N ; from source code
N [1..8]
Running at 80Hz was very loud - buzzing / jerky motion
Idle % I V notes
92% 0.08A 12.6V noise started
84% 0.25A 12.6V air flow started
27% 1.5A 12.0V full air flow; completely open
0% 1.98A 11.6V full air flow; just burning current.
Running at 240 Hz - much nicer - very quiet. Effects settings:
Idle % I V notes
86% 0.23A 12.7V noise started
76% 0.45A 12.7V air flow started
50% 1.12A 12.5V full air flow; completely open
0% 2.05A 11.6V full air flow; just burning current.
Running at 400 Hz - <320>
Idle % I V notes
71% 0.52A 12.7V air flow started
50% 1.00A 12.7V full air flow; completely open
0% 2.10A 11.7V full air flow; just burning current.
Running at 800 Hz - high pitched - barely hear it, seems to hang more / jerky
Idle % I V notes
88% 0.14A 13.2 noise started
69% 0.66A 13.0V air flow started
50% 0.90A 12.9V full air flow; completely open
0% 1.70A 12.0 full air flow; just burning current.
For fun, I also did a direct connection to the battery:
2.68A 11.6V <valve>
This is close to what I had in my original notes:
1.35A for full open
2.8A direct battery connection without any resistors.
I'll probably run mine at 320 or 400 Hz. The buzzing seems to help get over a little stickiness (static friction) in the valve. Above 240 Hz, the valve no longer appears to vibrate back and forth.
I noticed that it is smoother from full air flow to no air flow than the other way around. I probably need to clean the valve. I am thinking carburetor cleaner should be okay for that.
If running it as just an on off valve, it looks like about 1 Amp will completely open it.
- Charles.
I looked at the valve a little more on the bench set up:
MS-11 V3 board, V2 idle air control fly-back installed
Code 2.68
Power source (11 'C' NiMh batteries that I use on my bicycle light - getting a little old...)
VDO 408.202/008/001 2 wire Idle control valve
Settings for PWM frequency = 80 Hz * N ; from source code
N [1..8]
Running at 80Hz was very loud - buzzing / jerky motion
Idle % I V notes
92% 0.08A 12.6V noise started
84% 0.25A 12.6V air flow started
27% 1.5A 12.0V full air flow; completely open
0% 1.98A 11.6V full air flow; just burning current.
Running at 240 Hz - much nicer - very quiet. Effects settings:
Idle % I V notes
86% 0.23A 12.7V noise started
76% 0.45A 12.7V air flow started
50% 1.12A 12.5V full air flow; completely open
0% 2.05A 11.6V full air flow; just burning current.
Running at 400 Hz - <320>
Idle % I V notes
71% 0.52A 12.7V air flow started
50% 1.00A 12.7V full air flow; completely open
0% 2.10A 11.7V full air flow; just burning current.
Running at 800 Hz - high pitched - barely hear it, seems to hang more / jerky
Idle % I V notes
88% 0.14A 13.2 noise started
69% 0.66A 13.0V air flow started
50% 0.90A 12.9V full air flow; completely open
0% 1.70A 12.0 full air flow; just burning current.
For fun, I also did a direct connection to the battery:
2.68A 11.6V <valve>
This is close to what I had in my original notes:
1.35A for full open
2.8A direct battery connection without any resistors.
I'll probably run mine at 320 or 400 Hz. The buzzing seems to help get over a little stickiness (static friction) in the valve. Above 240 Hz, the valve no longer appears to vibrate back and forth.
I noticed that it is smoother from full air flow to no air flow than the other way around. I probably need to clean the valve. I am thinking carburetor cleaner should be okay for that.
If running it as just an on off valve, it looks like about 1 Amp will completely open it.
- Charles.
Fiat - A great car for those who like to walk.