PWM-Idle question, hardware

Anders Karlsson · Post by **Anders Karlsson** » Tue May 16, 2006 3:35 am

MS1 V2.2 MT2.25 release MSnS-E 029q2
I´m going to try using the PWM-Idle function, and i have a question about the hardware mods.
I have a TIP121 transistor (hope it´s ok to use, culdn´t find a TIP122)
and i wonder if i should replace R16 from 1 kohm to 510 ohm?

Peter Florance · Post by **Peter Florance** » Tue May 16, 2006 4:24 am

I think 1k is fine.

TIP121 should work as well (80V vs 100V) as long as you include the diode across the valve's coil (banded end, cathode, goes to +12V)

Peter Florance
First Fives.Org - The E12 Registry
1981 Euro BMW 528i w/3.5L & Megasquirt Fuel Injection
1981 US BMW 528i "Repo Car"
http://www.firstfives.org
mailto:peter@firstfives.org (peter@firstfives.org)
ssr# 284

From: Anders Karlsson [mailto:oplenserdu@hotmail.com]
Sent: Tuesday, May 16, 2006 6:35 AM
To: megasquirt-mss@msefi.com
Subject: PWM-Idle question, hardware

MS1 V2.2 MT2.25 release MSnS-E 029q2
I´m going to try using the PWM-Idle function, and i have a question about the hardware mods.
I have a TIP121 transistor (hope it´s ok to use, culdn´t find a TIP122)
and i wonder if i should replace R16 from 1 kohm to 510 ohm?

Anders Karlsson
Opel Rekord -69
Turbocharged 2,2 litre CIH, MSnS-EDIS

This post is at: http://www.msefi.com/viewtopic.php?p=120224#120224

Posted by email.

Anders Karlsson · Post by **Anders Karlsson** » Tue May 16, 2006 6:01 am

Should the diode be connected between Fidle-out and 12V?
My Bosh valve also has another serialnumber, 0 280 140 502 instead of 505 but i´m guessing the only difference is where the hoseconnections are located. Could this be right?

Peter Florance · Post by **Peter Florance** » Tue May 16, 2006 6:16 am

Yes that's where it goes.
I don't know if there is any difference. Pin 1 to pin 3 should be about 2X resistance of 1-2 or 2-3 if it's what I think it is.

BTW sorry for hijack, but is there a valve like this with straight-through hose connections? That might fit hoses for aux air valve?

Peter Florance
First Fives.Org - The E12 Registry
1981 Euro BMW 528i w/3.5L & Megasquirt Fuel Injection
1981 US BMW 528i "Repo Car"
http://www.firstfives.org
mailto:peter@firstfives.org (peter@firstfives.org)
ssr# 284

-----Original Message-----
From: Anders Karlsson [mailto:oplenserdu@hotmail.com]
Sent: Tuesday, May 16, 2006 9:01 AM
To: megasquirt-mss@msefi.com
Subject: PWM-Idle question, hardware

Should the diode be connected between Fidle-out and 12V?
My Bosh valve also has another serialnumber, 0 280 140 502 instead of 505 but i´m guessing the only difference is where the hoseconnections are located. Could this be right?

Anders Karlsson
Opel Rekord -69
Turbocharged 2,2 litre CIH, MSnS-EDIS

This post is at: http://www.msefi.com/viewtopic.php?p=120255#120255

Posted by email.

Anders Karlsson · Post by **Anders Karlsson** » Tue May 16, 2006 6:42 am

I´ll try to make a "text drawing". My valve looks like this:

^ out

in > : <--- this is the connectorpins

There are also valves that look like this:

in>---->out

¨ <--- connectorpins

Lousy "drawings" but i´ll just spend hours not being able to add a Paintdrawing here. Hope you understand anyhow.

Peter Florance · Post by **Peter Florance** » Tue May 16, 2006 6:49 am

Thanks Anders
The second valve sounds like it.
Do you know part # or what cars they came on?

Cheers

Peter Florance
First Fives.Org - The E12 Registry
1981 Euro BMW 528i w/3.5L & Megasquirt Fuel Injection
1981 US BMW 528i "Repo Car"
http://www.firstfives.org
mailto:peter@firstfives.org (peter@firstfives.org)
ssr# 284

-----Original Message-----
From: Anders Karlsson [mailto:oplenserdu@hotmail.com]
Sent: Tuesday, May 16, 2006 9:42 AM
To: megasquirt-mss@msefi.com
Subject: PWM-Idle question, hardware

I´ll try to make a "text drawing". My valve looks like this:

^ out

in > : <--- this is the connectorpins

There are also valves that look like this:

in>---->out

¨ <--- connectorpins

Lousy "drawings" but i´ll just spend hours not being able to add a Paintdrawing here. Hope you understand anyhow.

Anders Karlsson
Opel Rekord -69
Turbocharged 2,2 litre CIH, MSnS-EDIS

This post is at: http://www.msefi.com/viewtopic.php?p=120259#120259

Posted by email.

Anders Karlsson · Post by **Anders Karlsson** » Wed May 17, 2006 4:31 am

I found a valve that might suit your needs.
The Bosch partumber is 0 280 140 542, it comes from a Volvo 850 turbo.
Can probably be found in several other european cars too.

PSIG · Post by **PSIG** » Wed May 17, 2006 10:46 am

Peter Florance wrote:... BTW sorry for hijack, but is there a valve like this with straight-through hose connections? That might fit hoses for aux air valve?

Do you mean some of the 'T' style ones like on this page? http://www.autopartswarehouse.com/repla ... ement.html
It lists a few makes/models. If you need a used one I can keep it on my 'yard list as they are generally under $10 for an item like that. NAPA has the Standard Products AC388 below for only $399.

David

Anders Karlsson · Post by **Anders Karlsson** » Thu May 18, 2006 5:10 am

I will fill in with another question, about the resistor on the ground wire of the idle valve. Does it have to be 35-40 ohm? I have four 7 ohm resistors that can be connected in series to 28 ohm, would that be enough?

Anders Karlsson · Post by **Anders Karlsson** » Wed Jun 07, 2006 1:04 pm

Today i tested my PWM-idle setup. I think it works, but the idle rpm gets very high as the engine warms up.
At cold engine the idle was about 1200-1300 rpm, wich is ok. But as the engine got warm the idle rised up to about 1800-2000 rpm, wich is not ok.
Throttle response was very good though...
I may have connected the inlet hose to the idle-valve wrong. I use a connection on the throttlebody, just before the throttle.
Since it is a turbo install, i thought that as the engine warms up, the exhausts get warmer too, and the turbo starts charging.
The idle got lower when i squeezed the hose between throttlebody and idle valve.
I think i will try connecting it before the turbo, so there will be no pressure into the idle valve.
I tried some different values in the settings page, but nothing made any difference that i noticed.
My setup is Bosch 3 wire valve, TIP121 transistor and 24 ohm resistor pack to ground. I also have a 1N4001 diode between +12V and Fidle-out.
MS1 2.2 029q2 MT2.25 release

Jon k · Post by **Jon k** » Thu Jun 08, 2006 12:05 am

I am very interested in this - I am going to be trying this mod with my Bosch 3 wire valve in my BMW. Is it easy to build the circuit? I have a TIP122, a 50w 40ohm resistor in a heatsink, and the appropriate diode.

Peter Florance · Post by **Peter Florance** » Thu Jun 08, 2006 3:19 am

PSIG wrote:
Peter Florance wrote:... BTW sorry for hijack, but is there a valve like this with straight-through hose connections? That might fit hoses for aux air valve?
Do you mean some of the 'T' style ones like on this page? http://www.autopartswarehouse.com/repla ... ement.html
It lists a few makes/models. If you need a used one I can keep it on my 'yard list as they are generally under $10 for an item like that. NAPA has the Standard Products AC388 below for only $399.

David

Sorry I missed your post. Yes that's what I'm looking for!

Thanks!

MegaScott · Post by **MegaScott** » Thu Jun 08, 2006 7:47 am

PSIG wrote:...It lists a few makes/models. If you need a used one I can keep it on my 'yard list as they are generally under $10 for an item like that. NAPA has the Standard Products AC388 below for only $399.

David

Ahem...Is that....Three Hundred Ninty Nine......US Dollars? Are they nuts? They want people to buy this stuff?

Anyway.

It should look something like this when your all hooked up. You will still need to upgrade the Fidle transistor to something more robust; I.E. ZTX688, TIP1xx Ect...

Anders Karlsson · Post by **Anders Karlsson** » Thu Jun 08, 2006 7:54 am

MegaScott wrote: It should look something like this when your all hooked up. You will still need to upgrade the Fidle transistor to something more robust; I.E. ZTX688, TIP1xx Ect...

Just doublechecking. Pin 1 on idlevalve to FIdle-out, pin 2 to 12V+ and pin 3 to ground via resistor. 1N4001 connected between pin 1 and 2 with banded end to pin 2, 12V.
Right?

Jon k · Post by **Jon k** » Thu Jun 08, 2006 8:04 am

What would be the settings required so that this thing will work on start up? Know what I mean? How can we make sure that if we try and start the car first time we don't have an IAC closed issue.

Anders Karlsson · Post by **Anders Karlsson** » Thu Jun 08, 2006 8:13 am

If everything is wired up the right way the valve should click open when ignition turns on. Mine did anyway, and i removed one of the hoses to check that is really was open before i started the engine.
Although i must tune my PWM-settings some more, because rpm increased a lot when my engine got warmer.
Any suggestions on wich settings i should look at first?

Keithg · Post by **Keithg** » Thu Jun 08, 2006 8:13 am

in the 029 PWM idle code, you put a crankDC value in the block that is what you want it to be at startup. Piece of cake.

KeithG

MegaScott · Post by **MegaScott** » Thu Jun 08, 2006 8:44 am

Anders Karlsson wrote:If everything is wired up the right way the valve should click open when ignition turns on. Mine did anyway, and i removed one of the hoses to check that is really was open before i started the engine.
Although i must tune my PWM-settings some more, because rpm increased a lot when my engine got warmer.
Any suggestions on wich settings i should look at first?

Your understanding of the wiring is correct, The only way to know what the values are for your car is trial and error, pick some values and run it if it doesn't work, adjust to suit.

Anders Karlsson · Post by **Anders Karlsson** » Thu Jun 08, 2006 8:56 am

Ok, thanks! I´ll just keep fiddling around with it then.
This is the msq i run for the moment.
Edit: i changed from B&G on/off to PWM in the idle control when i tested it of course. Didn´t change any values very much though.
Tried warm up only and closed loop without any difference.

sportage4x4 · Post by **sportage4x4** » Thu Jun 08, 2006 10:52 am

just to add to this, i'm using a 3 wire bosch iac valve, and with the 'old' IRF540 way of controlling the valve it works perfect. however, i am now trying to use this new (and much simpler) way of controlling the valve and i have the same problem as Anders. the idle speed is very high. i can hear that the valve is not fully closed even at 0% DC. i have a 40ohm resistor on the closing wire. i'm afraid to try lower resistance values because as it stands the 40ohm gets very warm. any ideas?

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