Daimler double six 1979 AAV test?
#21
02-07-2017, 12:39 PM
So may I conclude that I cannot plug the AAV (inlet in the airfilter housing), not even in order to see if the AAV is open or not when hot?!
#22
02-07-2017, 08:16 PM
Of course you can.
With the engine running, put your thumb in the hole. The engine will probably stall.
This thumb method is generally used to establish other vac leaks, coz with the thumb in the hole, and the engine only slows down, you have other vac leaks, BUT, with no other vac leaks, the air bleed past the 2 throttle discs will barely be enough to keep it running.
At the end of any day, the only way to establish if that AAV is closing at operating temp is to look up the snout when the engine is hot, or remove that AAV and place the bulb in boiling water and look up the snout again.
It is a very basic, simple sliding sleeve valve. and the D Jetroniic system is also not smart enough to detect too much at all, these engines with that system, will run with all sorts of items misbehaving, whereas the HE will not.
With the engine running, put your thumb in the hole. The engine will probably stall.
This thumb method is generally used to establish other vac leaks, coz with the thumb in the hole, and the engine only slows down, you have other vac leaks, BUT, with no other vac leaks, the air bleed past the 2 throttle discs will barely be enough to keep it running.
At the end of any day, the only way to establish if that AAV is closing at operating temp is to look up the snout when the engine is hot, or remove that AAV and place the bulb in boiling water and look up the snout again.
It is a very basic, simple sliding sleeve valve. and the D Jetroniic system is also not smart enough to detect too much at all, these engines with that system, will run with all sorts of items misbehaving, whereas the HE will not.
Last edited by Grant Francis; 02-08-2017 at 04:55 AM.
#23
02-08-2017, 04:47 AM
You will need to remove and dismantle the AAV to see that.
I have refreshed many over the years, and that passage is simply there in the casting, and is an air bleed for idle adjustment when at operating temp.
I have never seen that passge clogged/grubby/contaminated., as it is too large a bore for that.
I have refreshed many over the years, and that passage is simply there in the casting, and is an air bleed for idle adjustment when at operating temp.
I have never seen that passge clogged/grubby/contaminated., as it is too large a bore for that.
#24
02-08-2017, 05:00 AM
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patpin (02-08-2017)
#26
02-23-2017, 02:50 AM
Hello again,
When an AAV doesnt function, is this caused by a defective bulb or is the bulb in most cases stuck in the housing due to dust or oxidation. Haven't got time to depose it but I saw with a camera that the AAV is open (engine cold and OK). (Since I work on the fuel tanks I cannot run the engine now). In the latter case, can I try with a unlocking spray (WD40 e.g.)(Presence of Teflon is a contra indication for that spray). Thanks fr yr answers!
When an AAV doesnt function, is this caused by a defective bulb or is the bulb in most cases stuck in the housing due to dust or oxidation. Haven't got time to depose it but I saw with a camera that the AAV is open (engine cold and OK). (Since I work on the fuel tanks I cannot run the engine now). In the latter case, can I try with a unlocking spray (WD40 e.g.)(Presence of Teflon is a contra indication for that spray). Thanks fr yr answers!
#27
02-23-2017, 03:55 AM
In the dozen or so I have dismantled and cleaned out, the bulb has been OK. 2 have been a tad lazy, but they do close off eventually.
The use of any "agents" has never worked for me. However, some have had a little short time success with that method, but eventually, a full clean is needed.
Open when cold is normal, its the 100% close at operating temp that is critical.
The PreHE AAV is a lot easier to remove than the HE AAV, so pop the hose off the top, and remove the 2 setscrews, and plonk it in a boiling water pan, and observe it slowly closing, or staying where it is.
The use of any "agents" has never worked for me. However, some have had a little short time success with that method, but eventually, a full clean is needed.
Open when cold is normal, its the 100% close at operating temp that is critical.
The PreHE AAV is a lot easier to remove than the HE AAV, so pop the hose off the top, and remove the 2 setscrews, and plonk it in a boiling water pan, and observe it slowly closing, or staying where it is.
#28
02-24-2017, 03:42 AM
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Grant Francis (02-24-2017)
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