92 Hatch DX, with 97 B20 block and 97 LS head, custom t3 turbo setup with vortech fmu, walbor 255, B&M fpr, greddy bov.......my problem is that my boost guage reads negative boost.....when i turn on the car the boost guage is at "20" under the "0"....and when i test the car....I can barely feel boost but the turbo spools lound and the guage needle goes up to "0" boost..somtimes it goes pass the "0" and hits 5 psi only.....what's wrong?

 

nothing, its supposed to be in vacuum at idle

get rid of the FMU and get real management

 

I would say nothing because your car runs in vaccum in idle... but I'd check your line to your boost gauge cause it could be kinked , mine was when I got my whole setup together.