Idle

rochey88 · January 19, 2011, 12:47:36 AM

If i rev my g40 then let the throttle go..... it like tries to idle then dies..? common on them? and sometime it dies when its warm on idle?

hayesey · January 19, 2011, 09:14:10 AM

might be a gunked up aux air value which sits on the water pipe under the inlet manifold. It's worth removing it and soaking it in petrol for a while to try to clean it out, they are expensive to buy new (and I'm not even sure if they are available anymore).

Jezza-7 · January 19, 2011, 10:38:03 AM

Got any pictures of the aux air valve? I got the same problem.

dub-disaster · January 19, 2011, 11:22:16 AM

It sits on soild water pipe under the Inlet manifold jezz. Can you clean it by just shooting some carb cleaner down the pipe

GR40 · January 19, 2011, 12:49:20 PM

I have the same problem but it got better over time for some reason! The pictures would be mostly appreciated!

hayesey · January 19, 2011, 01:14:46 PM

dub-disaster · January 19, 2011, 02:54:06 PM

Can you just shoot some carb cleaner down one of the pipes? As I think mine could do with cleaning but I've fitted my inlet now n dnt really wanna be taking it if again.

grungeisdead · January 19, 2011, 04:55:07 PM

its also reffered to an ISV (idle stabilisation valve)

its probably best not just to shoot alot of carb cleaner down the piping, unless you disconnect both end of the pipes that attach to the ISV.

to be fair its only a 20 minute job whipping the inlet manifold off, and it saves fannying about in the most awkward of positions, its usually a good time to take off the oil breather pod and clean that out at the same time if you havent already

Jezza-7 · January 19, 2011, 05:52:26 PM

I was gonna say thats the isv. I know what that is. I have got a spare one.

hayesey · January 19, 2011, 06:34:40 PM

some call it an ISV but it's not one,it's purely to let extra air in when the engine is cold. The problems start when it gets gunked up and/or the bimetallic spring loses it's springy ness and it continues letting in too much air when it's warm.

grungeisdead · January 19, 2011, 07:50:05 PM

my bad my hayes! ive been conditioned from my golf tinkering days on teh mk1 golf forum, however it is rightly stated in the haynes as an AAV.

boyzey · January 19, 2011, 08:01:40 PM

i no old fords are bad for isv sticking open and causing running problems, i just remove them and fill them with brake cleaner shake them bit, tip it all out and just spray a little bit off loobe in to try keep it free did same on my g ages ago not had any trouble

hayesey · January 19, 2011, 08:14:37 PM

Yeah that's what was going on in those pictures which are actually of mine about 7 years ago.

BIG E · January 24, 2011, 12:08:35 PM

If you need a new auxiliary air valve p/n 026133453 from v/w they are not cheap, I asked the price today on your behalf when i went for some parts for my GTI. Not cheap £124+ vat.

cheys03 · January 24, 2011, 01:54:16 PM

Possibly consider one from another car if you're not happy to pay VW full whack. I'm not sure what affect an ISV from a different car might have, I've always wondered about the differences though.

Golf Digifant - bigger for the extra CCs?
GT/NZ Digifant - smaller as there's no supercharger drag to cope with at idle?

Interestingly the G40 and Golf ISVs have very similar part numbers (though I know this means very little), may indicate they are physically similar. They're such a simple device I can't see there being much between them.