I just installed a Defi Boost Guage a week ago following IAMHUNG's HOW-TO and it was a breeze. I am new to this and never had an boost guage before. Anyway, is it suppose to read around 20's below the 0 point when the car is idling? I drove the car right after I did the install and boost was at 19PSI which I know is normal.

And the 1 last question.
The other day I had my EVO running for like an hour with the AC on while I was reading and I realized that my boost guage wasn't moving. It stayed at 0 while the car was idling, I knew something was wrong. I tapped the guage pod a couple of times then the needle fell back down to the 20 point. Then I shut the car off and re-started it to see if it was going to read proper it didn't. Same thing reading at 0. So then I took the car out for a spin when it was reading at 0 while idling, the needle start to move like after 20 seconds the car was moving. I let the car cooled off for lke 6 hours and it worked again. Is something wrong or the temp was too high that caused the guage not to work? Thanks

 

I have the defi D gauge and it reads 19-21in vacuum at idle with no A/C. It reads about 3in less when I turn on the AC. seems to me as if yours is defective since it gets stuck at 0 when it should be in vacuum.

 

It's working fine now. Reading at 19-22 in vaccum. but was wondering why it was reading at 0 when I had the AC on. Maybe the temp was too high? I kinda doubt that it is defective tho. But if it is I wanna exchange it now before its too late.