I purchased a mechanical colbalt vac/boost gauge and i installed it the same way i had my other one, but the other one was electrical. But almost the same thing. and i cant get any boost readings. Im only getting vac. When im driving the vac is around 15 to 20 and once i give it full throttle the needle go's back to the zero. so i dont know whats going on . any suggestions. either that or the gauge is defective.

 

Where are you connecting? I teed mine in with the line going to the fuel pressure regulator, and it worked great. Also check the owners manual for the gauge. Maybe there is a check valve that needs to be disabled?

 

i connected it through the one of the two vacuum lines. the 2 suckers that are right below the throttle cable. i dont know much but fast learner. where is the fuel pressure regulator located at. does the pressure regulator barb have anything to do with it. or can u post a pic on how u have ur setup

 

If your electric gauge works to read boost then it sounds like your cobalt mechanical gauge is faulty or needs to be set to read boost. I would get hold of Auto Meter and they should be able to help you out. Did you get instructions with the gauge? Take a look at them and it might explain what is going on with your gauge.

You should be able to connect to either of the nipples on the passenger side of the intake manifold. The FPR is on the driver's side of the intake manifold attached to the middle of the fuel rail and has a vacuum line going to the intake manifold. The vacuum line going to the brake booster can be used if you can find a T to step it down to 1/4" to attach the gauge line to.

Hope you get it working.

 

Appears to me that you have it hooked into the inlet side of the blower which will never read boost. You need to hook it into a source coming from below the blower, in the lower intake manifold.

Jody

 

if you put it in a place where the air is rapidly accelerating it will read vaccuum, same for a MAP sensor, think about how fuel is sucked into a carb......

 

Agreed.

 

well thanx guys i finally got the gauge to work the way it's suppose to. i hooked it up the way camcojb said and it worked. now the boost is reading 91/2 to 10lb. with the 10lb pulley on.

 

Jody