so i went to install my TRD boost gauge today to my 2001 4runner to my 2nd gen super charger i T'd into the FPR and the boost port when i turned the truck on all i got on the gauge was VAC pres when i gave it gas it went from 20 to 10 on the VAC side any ideas ????

 

Well you have to be making positive boost for it to register boost. Otherwise it will read vacuum under normal operation. Drive it WOT and it will make it out of vacuum and into boost. I don't know if you can even make boost without driving under load.

 

vas nailed it. Go drive it. Revving your engine in the garage isn't going to do anything but make noise.

Do some searching online and see how much vac you should be pulling at idle at your elevation. If its low you either have leaks or a weak engine. A vac gauge can tell you alot about your engines health.

 

thank you for you help guys i will give it a try today

 

What they said, to see boost you have to make boost. With the SC you can see it for a second if you go full WOT while free revving but best to just go WOT while driving.