No vacuum on boost gauge

[sta1n1]

Hi

My boost gauge isn't showing any vacuum. Im 99% sure its mounted on the line that goes to the dump valve, should not I be having vacuum there? Where is an alternative place to mount the vac line? I am not a big fan of mounting it into the map sensor vac line or the fpr vac line...

[newsh]

Diaphragm split in DV?

[sta1n1]

could you please explain a little further since my english is not top notch ?

[newsh]

Ok, well you definitely should have vacuum on the DV line because it is vacuum that opens the DV. This means there must be a leak on the line or in the DV itself. It is quite common for there to be a hole in the DV where it rubs against the back of the headlight bracket or a split in the diaphragm inside it.

This is of course if you're connected to the right line, I'm guessing its an ABY and you've used the line that comes from the front of the inlet manifold. Also guessing that you have an original type plastic Diverter Valve.

[sta1n1]

thank you very much newsh.

Will be checking it out, you are correct in guessing that it uses the line that comes from the front of the inlet manifold, its an ADU, but it probably looks pretty much the same. Bought the car for a month ago so I am just sorting out various small problems. I have seen a receipt that they have installed a forge recirc dv for about two years ago, but I will have to check it out. In case I need a new one, which one will be a plug and play...fit and forget ?

[newsh]

Normally the Forge valve should be a piston type so no diaphragm to go wrong so maybe there is a leak on the line. The hard line you can see going behind the cam belt cover changes back to a soft line and runs behind the headlight down to the DV. make sure it hasn't split or popped off. I would recommend doing a boost leak test, you will easily find any leaks then and I wouldn't mind betting there are more than one.

[newsh]

Most people fit the DV from the S3, N17 I think.

[sta1n1]

ok thank you once again will have to find some equipment to take a boost leak test then. U are probably right in that it would be leaking various places.