vaccum problem?

[evo316g]

On my 90 GST when I am on the highway and I build like 5 psi and get off the gas real quick, and with it still in gear it will not pull vaccum. When it is doing this and I give it the least bit of throttle at all it builds like 5 psi and when I look at the guage it flutters back down to 0. Then just out of nowhere it will pull 12-15 on the vaccum side, at like 70mph in 5th gear. any idea on what could be going on?

thanks

 

[Defiant]

Your gauge is hooked up incorrectly.

 

[dsm dominator]

yeah its your guage, pull it out and inspect the line hose for kinks or holes, i knw when i first installed mine (autometer) i kinked the hose when i crammed ir in to my a pillliar pod.
i kinked it so bad that i read 1 vac and like 1.5 psi