AndyPen

iTrader: (24)

Cana stuck dump valve cause the car to idle at around 1500 - 1800 after a great day blasting around? Everything seems to work otherwise and the car (450 bhp set up rs500) is going like a dream. I don't think the valve should continuously hiss and bleed air at those revs??? Only started to happen as I got home. Am I right on that?

(its bailey item btw)

Alternatively - do the idle control valves just give up maybe? Electrical connections are good (new plug even) and its in nice and tight.

Big grin after a terriffic day of blasting around- would be nice to do more soon - any thoughts anyone?

Paul_RS

iTrader: (4)

I had the same problem on my RS 500 setup and removing the standard dumpvalve cured it. I'm guessing it must have been leaking from the small vacum hose connection somewhere?

Try pulling the small vacum hose off and covering the end with your thumb. When did that to mine the idle dropped from 1300 ish to 950.

So the valve was swiftly removed and all connections blanked off.

tabetha

It's a BAILEY!, nuff said, get used to it or change it, no it should not be hissing it is probably piston type(?) famous for this.
Personally as I am a chav I use a diaphragm type group a for the hiss on every change!!
If not the dump valve it is defo air leak, try covering outlet holes to see if it drops idle to confirm it is this first.
tabetha

rinus_2005

iTrader: (1)

the hissing is normal, those baileys can be open at idle, since the manifold has a vacuum strong enough to open the dv.
When you changed the dv recntenly is could alter your idle. Air will be drawn into the dv since that's less resistance than via the turbo. So engine could idle slightly higher revs.
the sucked in air will cause the hissing sound.

AndyPen

iTrader: (24)

Will check again but think its blowing as opposed to sucking at idle... not sure... thanks for the replies and ideas - will check it out and post results.

Couldn't see any other leaks Tab - and she ran beautifully even after the hiss came in at a junction for the first time. As smooth as can be apart from that, even revved beautifully under load etc.

I haven't changed it recently Rinus mate - have been running on it for around 800 miles with no probs and it didn't hiss before yesterdays blast - but what a blast it was - luverly

Get back to you all - thanks again,

Andy

AndyPen

iTrader: (24)

Been out with it tonight and as things were cold I got a good feel around... one of the mounting screws for the lower 500 fuel rail had vibrated out and was sucking in air directly from there... hence the hissing.

It wasn't the dump valve at all!

Finger over the hole and the revs dropped... problem solved. Just hope I didn't over do it on a lean engine during my blast around - but all sounds tip top.

Thanks again for the ideas guys