3 wire pwm idle valve problem

[bmwmaster]

Hi,

im messing around with my idle valve since a long time but can't solve the problem. From the beginning i have the problem that it is not responding to small changes in duty cycle.

For example warm car is idling at 900 rpm good, idle valve is at 50 % duty cycle. For testing the valve function i manualy rise dc to see when rpm start to rise............. there is no change until 58 dc. Then the rpm rises but somehow with a long delay. The PID correction ist just working in the Range of -5 to +5 so it has nearly no effect when rpm is just little of. When i rise kp the effect is to strong, good idle correction is not possible. Also it seems as the idle valve would hang in some position. Somhow it looks that the current is not big enough to drive the Valve when just small changes are needed.

I hoped that the last 1.110 Version would help but it didn't. So yesterday i installed two diodes, it also didn't help. Another problem occurred, EMU doesn't shut off anymore. It has still 6.2V current when i shut off ignition. Somehow i made a new circruit with the diodes.....it seems like when i turn off ignition, the idle valve is driven and recieves current which goes back to my fuse box and from there to emu
Im not electrician but made a pic how it is installed. Is there something wrong ???

Also i want to mention that the idle valve is connected through AUX 5 and AUX6 because i have heard that it is better this way.

[Kisielisodd]

You forgot about flyback diodes. Your valve works too slow

[bmwmaster]

Hi,

i have installed flyback diodes near the ecu, look at the pic which i uploaded. Is this position not good ? not working ?

Should i install them near the idle valve ?

[Kisielisodd]

That's right, flyback diodes are there.

Can you share log file ?

[Jadzwin]

You powerup the EMU via diodes. Connect the +12V side of diodes to fixed 12V not to switched 12V..

What is your PWM frequency ?

[bmwmaster]

ok thx, i will change to fixed +12V.

Frequency is 100 Hz. Also i wil make log file later.

[Jadzwin]

Try higher freqency

[bmwmaster]

Now i tested more with the 3 wire idle valve. Rised frequency to 200hz without change.
I continued measuring with oscilloscope, the output from emu end signal on valve looked good. About 12V and nice variating DC control.
Somehow mechanicly the valve doesnt react to small DC changes near 50. Its somehow not sensitive enough to changes in small area. As its an old type ov valve from an bmw e30 (i already tried several of them) now i will test an more modern valve from an newer modell.
I hape it helps....

[Jadzwin]

There are 2 types of 3 wire PWM valve. One with the spring and one without.
You have probably the one without spring. And actually this one will not work with EMU correctly.
For next software release this kind of idle solenoids will work with EMU

[bmwmaster]

There are 2 types of 3 wire PWM valve. One with the spring and one without.
You have probably the one without spring. And actually this one will not work with EMU correctly.
For next software release this kind of idle solenoids will work with EMU

Good to know....thx.....

Is it maybe possible to add aditional control possibility for idle control rpm ?
What i experienced now is that when decelerating and closing throttle for example at 4000 rpm the rpm is falling very fast.
Idle rpm is set to 900 rpm and idle control is activated at 2000 rpm.

When rpm goes below 2000 rpm while still falling, the idle valve adittionaly try to reach 900 rpm and lowering dc !!!

This causes rpm to (maybe) fall faster......

I also observed the idle control of my original (ecu) bmw e46.
The control somehow works better. When rpm is falling very fast, as the idle contol starts.....it catches rpm for example at 1100 rpm and than slowely lowers it to the given point.

Maybe a kind of blending would work.
Or something like go for 2 sec to 1100 rpm and then to 900 rpm.
I also tried to work with the rise rpm when VSS is higer but it didn't help much.

Maybe all didn't work because of 3 wire valve without spring, i will try with new software.
When the control will work then it makes more sense to play wit pid settings.
Adittionaly enabling ignition will make it i think....... because it now isn't too bad, its just not perfect enough.

[bmwmaster]

Today changed to another type of 3 wire valve (an more modern one and i asume with spring) and after adjustment it works perfect........

[shrek69]

There are 2 types of 3 wire PWM valve. One with the spring and one without.
You have probably the one without spring. And actually this one will not work with EMU correctly.
For next software release this kind of idle solenoids will work with EMU

Any News to this ?
Where to fetch the new Software.

[ATS_Scott]

There are 2 types of 3 wire PWM valve. One with the spring and one without.
You have probably the one without spring. And actually this one will not work with EMU correctly.
For next software release this kind of idle solenoids will work with EMU

Any News to this ?
Where to fetch the new Software.

http://www.ecumaster.com/testVersions.html

[Bimmer]

You powerup the EMU via diodes. Connect the +12V side of diodes to fixed 12V not to switched 12V..

What is your PWM frequency ?

Sorry me for my bad english, do you mean EMU must be powered with diode ? Or EMU must be connected to fixed 12v not ignition switch 12v ?

[Jadzwin]

No. EMU must be conencted to the switched 12V without diode.