MSefi.com read only forum (Jan.15,2018)

i have 2 fast idle valves to use at the moment 1 is a ford type which i assume is a simple solanoid as it only has 2 cables. it has 2 holes with what looks like a plunger going between the two, i also have a bosch type which again i assume is a solanoid which has 2 tubes, inside appears to be a rotating peice of metal to open and control the air flow.
correct me if i am wrong but i thought that if these items have no voltage applied to them then the air flow should be blocked and it should open when voltage applied???
except both of them if i blow through them the air sails through, i would expect if i blew through them that no air would come out???

cheers mat

Mat

Your Ford one is faulty,maybe needs a good clean,no air should flow when off...
John

I'm not familiar with the Ford type but as for the Bosch one, it sounds you might have one of the old style auxiliary air valves used in the CIS type injection systems. Those valves consist of a rotating disc which is activated by a bi-metallic strip. There's a heating coil wrapped around the bi-metallic strip, in it's normal mode of operation, battery voltage is applied to the coil whenever the engine is running and as the strip is heated by the coil, it slowly moves closing the valve over a period of about 30 seconds give or take a several seconds depending on the ambient temperature. IOW, it's OPEN unless you apply a voltage and when you apply the voltage, it closes slowly.

The interesting thing about this valve that makes it useful for some applications is that it does NOT need to be controlled by the ecu, you can just power it off of the ignition or fuel pump circuit and it'll do it's thing independent of any other inputs.

BTW, this is the type of valve I'm referring to, does yours look something like this?

the one idle valve i have looks like this

i also have this idle valve, can someone tell me if this is a straight forward on/off solanoid?
or is it a pwm job. if i connect 1 wire to ground and the other to 12v it behaves as if it is a dead short and that seems the same for several i have tried?
or is the case ground and the other 2 wires are to 2 seperate coils?

Mat,

The idle valve shown is also PWM type. It looks like one from 4.0 Ford Explorer. At the connector, the raised knotch side should be 12 VDC and the other pin is return. If you momentarily apply 12 VDC, it should fully cycle. But to get it travel part way to maintain a constant idle, PWM is used to apply partial power.

-Dennis