Extra air valve (EAV )
Discussion
Well I wish I had a warehouse full of them, judging by the number of PMs I've had 
Testing the EAV* is dead easy and I'd recommend doing it before you waste time and money because they're usually pretty reliable.
Simplest way: with engine cold, pull air pipes off the EAV. Shine a torch through from one side and observe a solid disc (brass-coloured if you're lucky, hacky black if not). There should be a crescent-shaped slot in the disc that's wider at one end.
Replace hoses, start engine and go for a spin. Once engine is hot switch hot, pull of hoses and repeat check. The slot should have disappeared if the disc has rotated like it's supposed to. If it fails this the EAV probably is FUBAR but might respond to a good wash in some solvent... petrol, carb cleaner etc.
With the EAV off the car and cold, observe slot as above. Now apply 12V from a battery or beefy power supply to the two terminals (avoid shorts). Watch the disc as over a couple of minutes it should slowly rotate and close off the slot. Remove power and as the unit cools, the slot should reappear.
In theory (I haven't tried it) you could also use a hot-air gun to heat up the base of the EAV which would simulate heat soak from the inlet manifold and close off the disc as above.
Edit *: I meant EAV, not AFM, dammit...
Testing the EAV* is dead easy and I'd recommend doing it before you waste time and money because they're usually pretty reliable.
Simplest way: with engine cold, pull air pipes off the EAV. Shine a torch through from one side and observe a solid disc (brass-coloured if you're lucky, hacky black if not
). There should be a crescent-shaped slot in the disc that's wider at one end.Replace hoses, start engine and go for a spin. Once engine is hot switch hot, pull of hoses and repeat check. The slot should have disappeared if the disc has rotated like it's supposed to. If it fails this the EAV probably is FUBAR but might respond to a good wash in some solvent... petrol, carb cleaner etc.
With the EAV off the car and cold, observe slot as above. Now apply 12V from a battery or beefy power supply to the two terminals (avoid shorts). Watch the disc as over a couple of minutes it should slowly rotate and close off the slot. Remove power and as the unit cools, the slot should reappear.
In theory (I haven't tried it) you could also use a hot-air gun to heat up the base of the EAV which would simulate heat soak from the inlet manifold and close off the disc as above.
Edit *: I meant EAV, not AFM, dammit...
Edited by Wedg1e on Friday 14th October 02:00
I did that with the AAD on the 280i...Electrically i didn't do shyte as you all know I'm an electrical dimwit...
But i de-gundged it with some brake cleaner and tested the mechanical operation by heating with a hot air gun and then putting it in the fridge...Trouble is the EAV on the V8 is a pig to get at let alone remove...I tried getting mine off a while back when i had the plenum off changing the fuel rail..I couldn't budge the bolts so left it as i didn't want to snap anything...I have a brand new unused EAV to fit....
But i de-gundged it with some brake cleaner and tested the mechanical operation by heating with a hot air gun and then putting it in the fridge...Trouble is the EAV on the V8 is a pig to get at let alone remove...I tried getting mine off a while back when i had the plenum off changing the fuel rail..I couldn't budge the bolts so left it as i didn't want to snap anything...I have a brand new unused EAV to fit....
Taking off the extra air valve requires small hands, small tools, patience, swearing and a bottle of gin.
To get in at the rear bolt, take off all the hoses and fuel lines and use a stubby spanner
I'd like to personally congratulate the person who put the connector directly above the bolt.
Once you have it off, use a Dremel or similar to create a screwdriver slot for the bolt. Makes putting it back on quicker
To get in at the rear bolt, take off all the hoses and fuel lines and use a stubby spanner
I'd like to personally congratulate the person who put the connector directly above the bolt.
Once you have it off, use a Dremel or similar to create a screwdriver slot for the bolt. Makes putting it back on quicker
Edited by MethylatedSpirit on Wednesday 12th October 23:05
MethylatedSpirit said:
Taking off the extra air valve requires small hands, small tools, patience, swearing and a bottle of gin.
I'd like to personally congratulate the person who put the connector directly above the bolt.
If you unplug the connector you should be able to get straight down onto the bolt. I've a feeling I might have used a 1/4" drive socket set with a long wobble bar but it has been a while.I'd like to personally congratulate the person who put the connector directly above the bolt.
Okley-dokley, here's a few pics of what I'm on about...
EAV hanging off a 12V power supply, as you see it's taking 400-odd milliamps:
...and the disc with slot (this is about as open as it gets):
After a couple of minutes it's started to move and close the slot...
Five minutes in...
...and eventually it's fully closed:
Here's another one:
...and some other spares...
Jag V12 fuel rail uses the same injectors as the 3.5L RV8:
...and this isn't for sale:
(original NCK-ported inlet manifold from the 390SE, the clue is in the inlet port sizes! I must get round to refitting it one day).
EAV hanging off a 12V power supply, as you see it's taking 400-odd milliamps:
...and the disc with slot (this is about as open as it gets):
After a couple of minutes it's started to move and close the slot...
Five minutes in...
...and eventually it's fully closed:
Here's another one:
...and some other spares...
Jag V12 fuel rail uses the same injectors as the 3.5L RV8:
...and this isn't for sale:
(original NCK-ported inlet manifold from the 390SE, the clue is in the inlet port sizes! I must get round to refitting it one day).
........
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...Probably not mate...
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