Simple Idle Air Control for aftermarket ECU SDS Megasquirt

[tomeric914]

Trying to think outside the box for a possible IAC valve on a 3.0 conversion to EFI using a 3.2 manifold. I know MS2 and MS3 has capability for PWM control of the stock 3 wire IAC valve, but I'm looking at either SDS or MS1.

I didn't like the options out there so far which are either a 5/16" fuel valve, a float bowl vent solenoid or an EGR solenoid valve. All were $50 or so and wouldn't exactly bolt right on.

Then it hit me, why not use a 12VDC solenoid valve like on a washing machine?



It's a normally closed valve so power is only applied when the engine is cold. The only detail I won't know until installed is what the resulting idle will be with the valve open. The hose size is either 1/2" or 5/8" so a restrictor of some sort may need to be put in line.

[psalt]

In general, I would avoid using washing machine parts on a Porsche engine. If you want something simple for cold idle, follow the factory and fit a CIS Auxiliary Air Regulator, it worked well for +100,000 Porsche engines. Many EFI conversions use them and there are plenty available used.

[Tippy]

I'm trying to understand how that can regulate airflow? Isn't it either open or closed?

[tomeric914]

Originally Posted by Tippy

I'm trying to understand how that can regulate airflow? Isn't it either open or closed?

It wouldn't regulate airflow. MS1 or SDS is open or closed for fast warmup or to increase idle for AC engagement. This is similar to 0 280 141 012 from an early 944.

[Tippy]

Ah, I see.

[sjf911]

Originally Posted by psalt

In general, I would avoid using washing machine parts on a Porsche engine. If you want something simple for cold idle, follow the factory and fit a CIS Auxiliary Air Regulator, it worked well for +100,000 Porsche engines. Many EFI conversions use them and there are plenty available used.

1+ This is what I did for a while and it worked fine, I even had the vacuum limiter plumbed in as well.