Dump valve open when idling?

[SP33DY]

I've recently had my engine to bits.

Yesterday when I started it for the first time and had my head in the bay checking everything was OK, I noticed that my dump valve was venting.

When pressing the accelerator it does close, then opens again when you back off.

I pulled the vaccuum pipe of it and there seems to be a massive difference in air pressure between the manifold pressure and the boost pipe pressure.

Is this normal?

I've had the dump valve on for about 2 months now and can't ever remeber it being like that?

Cheers.

[Andrew Cooke]

yes, there will be quite a difference in pressure, the clue is in the name - vacuum pipe.

You may be able to get different rate springs for your dump valve, a stiffer one will keep it shut at idle.

[RICHIE]

http://www.rtoc.org/boards/showthread.php?t=6865&highlight=Dump+valve+open+idling%3F&page=2

you will have to filter through the **** but the answer is on the second page fella

[SP33DY]

Nice one lads cheers for the quick replies.:)