4.6 idle valve

[jonnie_r]

I'm having a problem with idle on my MS2 setup on my 4.6, basically it's running about 1500rpm, sometimes creeps up but generally doesn't drop. I've had the idle valve unplugged and nothing has changed.

I've removed the idle valve today and there seems to be very little movement in it(maybe about 1mm). Would I be right in assuming that it is fubared? The coil also buzzes nicely when I plug it into the MS2 connector with the ignition on, which I take to be a sign that it is drawing current but not doing anything.

[Bowie69]

If you unplug an idle valve it will do this -you need it powered up and the duty cycle correct to bring the idle down -either that or bung the hole up. Unpowered an idle valve default to 'open' so if it failed, you would still be able to drive the car.

What plenum set up are you using?

[jonnie_r]

By open do you mean assembly extended or retracted? After having a google and checking photos, at rest they seem to all be retracted.

I managed to get the assembly to move by brute force, so extended it slightly, then refitted it. The idle is now at about 750-800, so I'm guessing that is where the fault would lie. The idle hasn't been right for a while, even with it connected to the MS2, the idle would never change from warm up to normal temp.

I am using the standard 4.6 plenum.

Thanks for the reply I am going to order a new valve and see what happens. It is quite possible the valve was done for as the car I got the engine from had been stood for about 18 months.