Car running fine dump valve not working
Turbo Mini Forums

Hi just been driving about in mini with metro turbo and noticed dump valve not working. Have changed for new one, but still nothing. Have connected boost gauge which reads nothing. Car definitely comes on boost and goes well and lots of noise from wastgate when changing gear? Any ideas thanks

Where's the sensor line plugged into?

Was it working before?

Was working before, it is on the side of the plenum chamber on the left, and the boost gauge is connected on the other side drilled into the plenum as well? Drove to the pub yesterday with three blokes and pulls well but the dump valve?

For an accurate reading the boost gauge should be connected into the inlet manifold. The small end of the dump valve also needs taking to the inlet manifold to.

Phil.

WWW.TURBO-MINI.COM

Cool, do you have a diagram please? Thanks again

Using search:
www.turbominis.co.uk/forums/index.php?p=vt&tid=2

Dazed and Confused....

This is very very simple.

The large (25mm) side of the DV is connected to the plenum just BEFORE the carb.

The small (6mm ish) hose on the DV goes to the inlet manifold. There is absolutely NO connection on the carb or plenum that will allow the DV to work.

The boost gauge needs to be connected to the inlet manifold. There is absolutely NO connection on the carb or plenum that will allow the boost gauge to work properly.

Ideally, the boost gauge and plenum need separate feeds from the inlet manifold, using separate hose tails that are drilled /
tapped into the inlet.

Do you a picture of where I should connect boost gauge thanks

No.
The inlet manifold is the part between the carb and cyl head. You can drill and tap a hose tail anywhere along the top face of it.

WWW.TURBO-MINI.COM

Just to make sure we’re on the same page, you obviously need to remove the inlet manifold before drilling and tapping it...

Or take out the banjo bolt for the servo pipe and drill that.

In the 13's at last!.. Just

Here you go:

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Thanks great help

As already mentioned the signal line for the dump valve needs to be plumbed into the inlet manifold not the plenum. They work on the principle that what the throttle is closed one side of the dump valve is subjected to less air pressure that the other allowing the piston to move. With both sides connected to the plenum they will always be at the same pressure and nothing will happen.

Also have you blanked off the pressure relief valve on the plenum chamber?

And if the DV is slow in operation, usually delayed, or giving a long dumping sound, you’ll need to replace the butterfly in the carb with a solid one that doesn’t have the poppet valve installed (or remove the valve and solder up the holes)...