I have a Blitz blm boost gauge and usually when I start the car the reading goes into the -#'s at idle but yesterday the needle sat at 0 and stayed that way at idle and when I drove out for about a mile. WTF? I checked the lines and nothing was pinched or disconnected. I turned the car off and on again and the same thing happened.

 

Sounds like pinched or loose vacuum line. Try putting the gauge directly to the T (assuming it's mechanical) and see if it makes any difference.

Dong Shin

 

Sounds like the tubing came off, is leaking, or got pinched.. Does it read under boost, but not under vacuum? usually that thats an indicator of a leak.. if it doesnt read at all, it could be the line got pinched, or if you have an electronic gauge, it could be the sensor got disconnected, again, if your reading boost pressure, but not vacuum, check all your connections again for a leak.. Its possible its something as simple as the ferrule inside the connector that fixes the capillary tubing to the fitting is cockeyed and cut a little hole (assuming your using that sort of vacuum line)

 

Ok, thanks guys. I'll check for leaks more thoroughly tonight. Have a lot to do tonight , MBC and Pruven Axle back going on.

 

definitely a leak or pinched line...