Vaccum/Boost Issue

[Willicuddy]

Ok my car idles at 750 rpm +/- 10 when the car is warm (temp guage at halfway mark) and my vaccum reads about 16-17. The needle on the guage vibrates a little when the car is at idle, it doesn't change the reading, just vibrates. This also happens when i have acheived full boost (MBC controlled max 15 psi). Im wondering if this has something to do with improper install of the boost guage, the kit came with a beefy rubber hose and not the crap plastic ones like the Autometer guages come with so im not sure that would be the iussue.

Also at idle engine shakes a little, not sure if this is normal or not because i don't have another dsm to compare it too.

My car deosn't read any knock and im running stock fuel/turbo. I also have a slight oil leak coming from my headgasket (Is almost non-existant after i changed oil brands/weight, but i thought i might as well mention it)

I did a little research and was maybe pointing to worn out valve guides for the vibrating guage needle.

any input is appreciated.

 

[SinaiTSi]

That vacuum really isn't too bad, 18-20 is a little better range though. Make sure all of your vac. hoses are hooked up properly obviously. The most important thing you can really do though is a compression test, it will tell you alot about how "healthy" your car is.

 

[Willicuddy]

Probably true, im taking the car to my mechanic to get some suspension stuff done, so i will get him too do a comp test real quick.

 

[Willicuddy]

I just went over all my vac lines and used all new rubber hoses. While i was messing around i decided to take off the MBC and hook the wastegate directly to the compressor housing and im sitting at a solid 11-12 psi so i'm assuming i don't have any leaks... also got my mechanic to do a boost leak test when he installed my FMIC and all checked out fine.

 

[oldman]

Boost leak test.

 

[steve]

I'm sitting at a solid 11-12 psi so i'm assuming i don't have any leaks...

That's a bad assumption, without testing you won't know for sure.
It's possible to get a solid 11-12psi and be overworking the turbo while the intake leaks like a sieve.

Steve