MS PWM idle question!

[slow325isedan]

Ok so new to MS, I have MS2 and just got my car back together, runs great so far just can get it to hold and idle, car just stalls won't even try to idle. I have the idle control set to PWM and I am running the stock ICV, any help on what to do would be greatly appreciated! Am I better off just not running the valve? The car is not my daily, but would prefer to run it. If I have to run it without the ICV what do I need to do to make that happen?

89 325i turbo m20

Thanks guys, any input is greatly appreciated!

[Whit3 E30]

First of all you need to find out how the stock I.C.V worked. Was it controlled by P.W.M to begin with or is it a stepper motor which varies position but "stepping" the voltage up by a set number each step.

[blueapplesoda]

Are you running idle pwm open-loop (warmup) or closed loop?

[EatsHondas]

How are you driving the valve? I mean, what kind of circuit(s) did you build in the ecu in order to send high current to the valve?

Correct me if I'm wrong, but I thought running the stock e30 PWM valve is not possible without installing an additonal TWO transistors for the valve, inside the ms2 case. There are two coils in the valve, one opens the valve when it receives a signal, and the other will close when it receives a signal.

There are folks that have wired up one coil with a transistor, and the other to a massive resistor with limited results, but this is a ghetto approach. The e30 valve is not designed to operate this way. With only one driver, the valve is constantly fighting itself to stay in the same position (ie. smooth idle).

Imagine a big crate on the floor, with you and a buddy standing on opposite sides. You decide you want to move it 5 feet towards your buddy, and each of you can only push. Instead of your buddy letting you push the crate, he pushes back and forces you to work harder in order to move the crate where you want it. And even after you move the crate, your buddy keeps pushing on it, forcing you to apply an equal constant force to keep the crate where you want it. See how dumb that is?

But to answer your question, I need to make sure you made accommodations inside the ms2 case for the idle valve. It will not work without this step.