I can give my car like 30% throttle and my boost gauge needle shakes real bad between 0 and 5 PSI. once I get around 3000 - 4000 RPMs it will stabilize.. At full throttle once it reaches 14PSI it will shake badly again, and then drop down to 10PSI of boost after 6000 RPMs.... https://www.nopistons.com/forums/pub...1047683561.gif



What do you guys think..??? maybie a Boost leak.. could it be a wastegat issue, maybie a shoddy turbo..??? Or even a bad missfire..?????



Thanks for any input..

yes to any of those.



where is the boost gauge plumbed in? if its in a runner it'll do that

It is sharing a line with the MAP sensor wich go's right to the manifold... It even shakes as soon as you start to accelerate when the gauge is still reading vaccum..??? but holds steady when at a idle..

maybe a slight boost leak check the vacuum at idle it should read 17-20hg

It reads 11hg at idle... Damn, What could be leaking.?? This will be a fun one.

good luck idk turbos wish i did

MY take might be a little different than the others....but maybe cheaper too:



Most boost gauges use a restrictor pill (either inbuilt or inserted into the line) to smooth out boost pulses. I experienced the same problem after installing my boost guage on my 240SX. The needle bounced around like crazy once I got on the throttle. The solution was I forgot to install the small bass restrictor pill due to the stupid japanese instructions. Once I spliced that into the line the guage read perfectly. First try holding the guage to make sure its not just picking up vibrations. If it still shakes try the restrictor pill.

Test with another guage first. Sounds like a gauge problem.