needle bounces around on boost gauge

[boost_creep]

i have a mostly stock s13 redtop.i recently installed a autometer cobalt boost gauge.it works great.a few weeks later i put in a joe p. mbc set to 10psi.i pressure tested the system and theres no leaks.i have the bov recirced.when i reach full boost,the needle bounces around between 10 and 11-12.i had the joe p. a while ago and sold it to a friend ,then bought another.my old one never did this.i know these style mbc have a bleeder that releases the backpressure from the wastegate.when i pressure tested the system it was pissing out of the hole,but didnt mind it cuase i figured thats what it should do.any suggestions??

[95gstnj]

I'm having the same problem on my redtop with an avcr. my manual boost gauge bounces really fast between 8-10psi, and my avcr reads about 14 psi. with that info, the only thing i could think of would be a small crack in the plastic tubing to the boost gauge, or a leaky t fitting where you tapped for your boost gauge. I'm going to pull mine out and see. if i find out, i'll let you know.

[boost_creep]

where do you have your boost gauge t'd.off the fpr?thanks.

[Silverbullet91]

I've just replaced my Autometer mechanical boost gauge with a Greddy electrical gauge because the cheap pos Autometer failed and leaked and made a horrible noise. Not a hose or fitting, but the gauge itself. After only 5 months of use! In my opinion, stay away from the Autometer mechanical boost gauges. They are cheap, inaccurate pieces of crap.

[da40]

most obvious is a boost leak somewhere check lines and the fittings