Vacuum value

What would a good vacuum reading at idle be with a vacuum gauge on a BRM engine? Thanks

Where would the vacuum gauge in question be installed?

I ask because there's no vaccum per se at the intake manifold, so what you read will depend on where in the vacuum system you are looking; at the vacuum pump, on the other side of the N75 valve, at the actuator, etc etc.

If you are in fact referring to the output of the tandem (vacuum) pump itself... most people report around 25" at idle.

Thank you. Thanks what I meant.

Check the vacuum reservoir in the cylinder head cover for leaks. They can leak slightly and it will not be particularly noticeable or throw a code. Mine leaked and it took me years to figure it out.

I will. Mine starts out in the morning ok no black smoke. Later in the day when it's hot it blows black smoke. Checked it when I got home after a 100km drive on the byway & I am getting the 25 inches off the vacuum pump. I'm going to drive with the meter again & see what kind of vacuum I get.

Seriously, check all your vacuum line hoses. If they are the originals, they are at least 12 years old, hardened and perhaps no longer capable of maintaining a seal. It sounds like your pump is good, but there are many points of potential leakage. I uploaded a diagram some time ago that you may find helpful:

http://pics.tdiclub.com/showphoto.p...-vacuum-lines-and-components-in-color&cat=516

Thanks I now have 3 sets of hoses. I new vacuum gauge plus 2 older ones. I did have a bad check valve but I replaced it. I will check the vacuum storage though.

All good with the hoses. Storage tank good as well. When I get back home Monday I'm going to hook up the meter & check the turbo. I don't hear it as I do with my daughters horse 06 Jetta TDI.

Got home with the car put the meter on it as engine light came on. 00257. Checked the boost pressures.On actual vs what it should be varies from 50mbar to over 1000mbar. Needless to say she blows black when 1000mbars from normal. I cant find an answer for that code number but I'm thinking the turbo is pooched. I can't hear it spooling.