Aux Air Valve Question
#2
Team Owner
it is supplied with 12v all the time ,
once 12v is removed then the valve inside will move to its cold open position
once 12v is removed then the valve inside will move to its cold open position
#3
Rennlist Member
Kinda dumb isnt it? Or does it stop getting 12v when the thermotime switch opens?
My WUR (K-jet) has two windings on its bi-metallic strip, and I think one of them isolates 12V when the strip is fully heated by engine heat. The same could apply to the AAV...
jp 83 Euro S AT 54k
My WUR (K-jet) has two windings on its bi-metallic strip, and I think one of them isolates 12V when the strip is fully heated by engine heat. The same could apply to the AAV...
jp 83 Euro S AT 54k
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#8
Man of many SIGs
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The temp time switch turns OFF the signal to the heating element inside the aux. air valve. By that time, the aux. air valve should be thoroughly heat soaked from the engine heat.
In case you don't know how it works. there is a bi-metalic strip inside it. The bimetalic strip is resting against a "wheel". The wheel has a little tit on it's outside edge so that as the bi-metalic strip heats up and bends, it rotates the wheel. The wheel has a very irregularly shaped hole in it that allows air to bypass during warm up to bring the idle speed up. The cold position of the wheel is fully open. The hot position of the wheel is fully closed. The bi-metalic strip has a heating element wrapped around it. The temp time switch sends a 12v signal to the heating element to begin it's warm up. The engine heat that wicks into the aux. air valve is what keeps the wheel in the "closed" position. If you want to see it for yourself, just drill out the rivets holding the whole thing together. You can re-assemble using small bolts.
In case you don't know how it works. there is a bi-metalic strip inside it. The bimetalic strip is resting against a "wheel". The wheel has a little tit on it's outside edge so that as the bi-metalic strip heats up and bends, it rotates the wheel. The wheel has a very irregularly shaped hole in it that allows air to bypass during warm up to bring the idle speed up. The cold position of the wheel is fully open. The hot position of the wheel is fully closed. The bi-metalic strip has a heating element wrapped around it. The temp time switch sends a 12v signal to the heating element to begin it's warm up. The engine heat that wicks into the aux. air valve is what keeps the wheel in the "closed" position. If you want to see it for yourself, just drill out the rivets holding the whole thing together. You can re-assemble using small bolts.
#9
Rennlist Member
Mine played up a while ago and didnt open enough to prevent occasional stalling during warm up. I removed, drilled out the rivets, and managed to get it to open enough for ~1100rpm idle when really cold - couple of tests in the freezer, bending the spring anchor point, re-seal with m6 bolts.
If yours gets very hot quickly, sounds like the heater wires may have shorted?
jp 83 Euro S AT 54k.
If yours gets very hot quickly, sounds like the heater wires may have shorted?
jp 83 Euro S AT 54k.
#12
Man of many SIGs
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#13
Burning Brakes
Join Date: Nov 2010
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The talk of 12v had me wondering. No 12v connection like that as I remember on mine.
PET shows 2 caps instead of the rubber hoses that I bought and installed when I removed my aux. air valve.
PET shows 2 caps instead of the rubber hoses that I bought and installed when I removed my aux. air valve.
#14
Addict
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Thread Starter
So looking at the wire diagram looks like AAV (Start Valve) gets constant 12v and the ground is switched off when the thermo reaches temperature. Right?
#15
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Join Date: Jul 2010
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The AAR is actually listed as the "Supplementary AIR valve" in the wiring docs for my 81 Euro car (not "start valve"), and gets constant 12v when the fuel pump relay is activated. Start Valve refers to the cold start fuel injector.