Ecumaster forum

I had it come in a pnp adapter but it isnt working so I'd like to wire the solenoid directly to EMU, there are 2 wires in it and I know it doesnt have the polarity so it doesnt matter which one goes into what.

Question is where to connect these 2 wires.

1 wire goes to EMU Output (G4 in my case)
1 wire goes to the 12v fused power supply or to a ground?

I dont want to fry anything so I'd like to be careful.

Thanks in advance.

shoudl go to 12v power. You want to put a flyback diode in place.

What is the reason for the flyback diode? Does it go in parallel with the solenoid?

When the solenoid is switched off, the field of the coil is breaking down, which creates a voltage spike, that voltage has switched polarity.
This voltage could damage the voltage source(e.g. the emu), and or powering it thru the output.

You have to connect it anti-parallel to the source.

for mac valve it is not necessary to ad flyback diode EMU will handle it without.

Could you please elobrate? Do all mac solenoids have a builtin diode, or just certain models. -thanks

There's not a built in diode in the Mac valve but the amount of back EMF is not enough to worry about, unlike something like a VVT solenoid.

High current, high frequency solenoids are what necessitate flyback diodes. A boost control solenoid doesn't use enough current to necessitate a flyback diode, nor does it run at a high frequency.

Kisielisodd wrote:for mac valve it is not necessary to ad flyback diode EMU will handle it without.

Can a boost control solenoid on 20- 30Hz be driven by stepper motor output ?

its a pierburg valve form VAG , or vauxhall.

part number : 7.00470.07.0
they are crazy cheap like 25 -30 euro's FEP connector is like 3euro, and work perfect for simple bleed boost controll.