I just finished installing a single turbo on my 88 turbo II. I started the car up and had no vacuum on my boost gauge(its aftermarket). I have an HKS wastegate and turbo xs blow off valve. I was thinking there might be too much vacuum line and the gauge can't get a reading. Any suggestions? The car will sit and idle no problem.

 

where did you tap the line for the gauge?

 

You probably tapped the vac source before the throttle body.

 

I fixed the problem, I had too many vac lines off of one source. I routed the boost gauge to the twin scroll vac port (since its gone) and I got a vac reading.

 

It should be on the port for the boost sensor