In my quest for fuel economy – and in the interest of having more gauges and fancy lights in my car – I installed a vacuum gauge. Since I drive a car made well prior to the advent of ODB-II I am left out of all the fun electronic things one can plug in that way I must instead resort to old-school mechanical-type things, like a vacuum gauge.
I though I’d document it since the forum people say, essentially, you hook it into the manifold or vacuum line, you can figure it out, it’s not hard. They’re right, but I like photos. So here they are.
First, I found an inexpensive gauge on eBay, which was $16 shipped. I would have also said cheap but it turned out to be fairly well made, with all the necessary parts, and appears to be accurate. Win!
And a note on compression fittings: yes, they just go together like this and you winch them down. I wasn’t sure about it since the tubing slipped out when finger-tightened but wrench it down and it locks and seals fine.
The first (hardest) part was figuring out how to get the vacuum line through the firewall. I finally found a helpful forum post (it was too cold to just go hunt around too much) that mentioned the gasket around the throttle cable. It’s the same one that a couple of the large wiring harnesses go through and (with a bit of poking and prying with a screwdriver) the vacuum hose fit through as well.
And the finished install (except for backlight wiring). I’ve done the wiring, but haven’t photographed as that taps the dash lighting circuit behind the headlight switch and is impossible to take meaningful photos of.