2 Pin Idle Air Control Solutions - Rover Manifold
Turbo Mini Forums

I am using a Microsquirt based system that needs to use a 2 pin IAC. Supposedly VW, Saab/Volvo and Ford all have had 2 pin IACs at some point.

Has anyone tried any of these with a modification to fit a Rover MPi manifold?

There was a thread sometime ago where someone had used a Magneti Marelli from a Peugeot that mated well to the Rover housing attached to the manifold. It uses a 4 pin connector as it is a stepper which can be controlled by the MS2 IAC circuit which the Microsquirt does not have.

I have seen the Bosch version for VW as high US $300 over here and a generic Ford version for US $50. I am not sure how difficult it will be to modify either to fit.

Any ideas are welcome

Rover MPi IACV with housing

I use that body with a Peugeot IACV valve on the MS2 and MS3. However, that will not work with a Microsquirt.

The difference is that the MS2 and the MS3 have a stepper driver chip. The Microsquirt is limited to a PWM output.

A 2 or 3 wire idle valve can be made to work with the FIdle output. Have a look at the MS manuals.

You will need to block off and/or adapt to the existing port on the manifold.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Just to add to what Terry mentioned, he is using one of my Microsquirt module based ECU housed in a ruggedized enclosure.

A 2-wire idle valve can be used directly from the module IDL output and there are 6 additional outputs that can also handle the current. The issue for Terry is to minimize the amount of fabrication needed so any 2-wire valve that could be used in place of the stepper motor would be great.

There is a possibility for a software solution for using the original 5-wire stepper. That would use 4 of the aforementioned 6 additional outputs and would require modifications to the MS2/Extra code and the on-board MiniIOx code.

I want to add a stepper motor feature to the IOx code so that would be one more application. However, I would also need to modify the MS2/Extra code to send the stepper count over CAN.

So if no one knows of a potential 2-wire valve and if Terry's timeline for needing the feature is not too tight, that would likely be the ideal solution. It would also be something other IOx users could benefit from.

Jean

http://www.jbperf.com/

The Ford version is pretty common over here.
This one with an exterior feed similar to the MPi style.


And then this one with an integrated feed/supply where the air supply is on the same side as the manifold feed.


As Jean says, it is just the amount of fabrication that is required to make it work.

The Bosch version uses two separate connections and is not mounted or attached to the manifold.

Edited by tmsmini on 4th Feb, 2014.

just fit a hose connector to the MPi manifold and you can fit the Bosch valve quite easily with a piece of hose. if you use the MPi throttle body you just fit a hose back to it from the idle valve and your done

Looks like Bosch is three pins


but I know it is mentioned on MSEXTRA

The best way to drive the 3-wire Bosch valve is to use 2 outputs. However, that would require some code changes or external hardware. The code change would not be too much work so if you want to go this way let me know.

You can use a resistor to ground as shown here: http://www.msextra.com/doc/ms2extra/MS2-Ex...dware.htm#Fidle However this is not the best way to drive the valve.

http://www.jbperf.com/

On some other forums people are talking about 2 wire Bosch valves, so they must be out there...just have to keep looking.

PS: found this one ebay. It ought to do for some testing, looks like it comes with a bracket as well

Edited by tmsmini on 5th Feb, 2014.

Terry,

The very "old" Bosch valve, that is pictured in the MS-Extra manual pages Jean linked you too, is still available secondhand over here. It was commonly used back in the 80's in Europe on the very early Bosch K-Jetronic and L-Jetronic injection systems. But they are expensive, approx £40 (so about $65) second hand on eBay UK.

EDIT - link added to a typical eBay one
http://www.ebay.co.uk/itm/IDLE-AIR-VALVE-M...=item53f00c42a8
END - edit


The one you have found and photo'd may just be a later version of the one pictured in the MS-E manual.
They are crude, just a bi-metal strip to open/close a disk valve so idle has to be set on the throttle plate, they only deal with warm-up.
I think I have one buried somewhere in my shed if you get really stuck although postage to the USA won't be cheap.

Jean,

Edited by Rod S on 5th Feb, 2014.

Schrödinger's cat - so which one am I ???

Rod,

This is indeed mainly interesting for those with a Microsquirt or a Microsquirt module based ECU when we're talking about an idle valve. However, stepper motors can be used for other things which is also why I want to add this support to the IOx.

In Terry's case, that would not require the addition of any hardware because there are already 6 medium current outputs available. And a 5 or 6 wire stepper only requires 4 grounding outputs not the 2 full h-bridge circuits of a 4 wire stepper.

That also means that an IOx user (full one not OEM) could also use the on-board hardware to control a 5 or 6 wire stepper using 4 of the 6 high current outputs.

One advantage over using the MS2 or MS3 stepper motor controller is for those with 5 or 6 wire stepper motors. Some do not work very well with the 4 wire controller.

And for those with a module based ECU, adding a TinyIOx with either a stepper motor controller chip or discrete components would be a good way of using a stepper motor valve and not lose the possibility for sequential injection.

Jean

http://www.jbperf.com/

Schrödinger's cat - so which one am I ???

I'm looking for an alternative to the stepper idle control.

Although the 4 pin valves are readily available, the valve bodies are an issue. Either buy an expensive body or use a Rover one and make a flange to suit.

It would be a lot easier to use a simple 2 or 3 pin Bosch valve, but new valves are expensive.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Nothing off topic that I see. It seemed the EFI section was a little quiet the last few months...

Terrible photos, but I made a little progress in finding a potential place to mount the Bosch IAC.
Blocked off the port for the Rover valve, mounted a plate for the Bosch, just trying to figure out hoses. In one of the photos you can see the Rover hose. I just need to insert the Bosch IAC inline. Also need to make sure my crude plate will seal properly. And I am worried that the weight of the Bosch IAC may be too much for the plastic Rover IAC mounting body.

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