Boost guage problem

[Pressured]

I just hooked up a boost guage on my GTS. I spliced into the line going to the Vec2 for the vacum/boost signal to the map sensor for the guage (electric guage). Reads boost great, but at idle I get a zero reading for vacum. Steady cruise vacum reads ok but not at idle. Also, there only seems to be a tiny bit of vacum from the line at all. The line originates from the nipple that came on the Roe intake by the by-pass valve. What am I missing?

[1TONY1]

Why would you get an electric boost gauge instead of mechanical ? You should temp hook up a mechanical to see how it compares with the electric.

[GR8_ASP]

Not sure what is wrong with an electronic boost gauge. I have one and am very happy.

Most boost gauges zero themselves during their start-uo routine. Seems like something is getting messed up during that. Also, a vacuum leak on the path that your sending unit is on can lead to misleading results.

Question, is the sending unit one made for the boost gauge or is it one you already had? May be a compatability issue.

Just some random thoughts.

[Pressured]

To be honest, I got the electric gauge because the local speed shop was out of the mechanical. I am using the map sensor that came with the gauge. Is the nipple by the by-pass valve the only source for both vacum and boost?

[1TONY1]

Not sure what is wrong with an electronic boost gauge. I have one and am very happy.

Most boost gauges zero themselves during their start-uo routine. Seems like something is getting messed up during that. Also, a vacuum leak on the path that your sending unit is on can lead to misleading results.

Question, is the sending unit one made for the boost gauge or is it one you already had? May be a compatability issue.

Just some random thoughts.

Nothing is "wrong' with one, but it has more stuff to mess up. The sending unit is an extra part and the gauge is more prone to messing up imo. It's no harder running a wire than it is to run an 1/8" tube. I just don't like electric gauges. Even with fuel pressure I have always ran mecanical with an isolator.

[1TONY1]

To be honest, I got the electric gauge because the local speed shop was out of the mechanical. I am using the map sensor that came with the gauge. Is the nipple by the by-pass valve the only source for both vacum and boost?

That nipple should work....it is the one that goes to your vec2 ?? I have a dedicated drilled/tapped hole for mine.

[Joseph Dell]

Make sure that the electrical gauge does not lose power during cranking. That gauge MUST not re-calibrate itself else your readings are off. If you hooked it into the fuse box, make sure you got power from fuse #10. If not, that may be your issue...

good luck!

BTW - Tony - electrical gauges are nice b/c they have both PEAK (with a light) and memory so that you can see what the highest recorded boost was since last reset. that is why I have one... But truth be told, it is a PITA... I will probably switch back to mechanical.

JD