Needle on vdo boost gauge shaking?

[6SENSE]

Any ideas what would cause this? Starts happening under boost >21-22~psi. Needle starts going crazy moving back and forth. Just want to make sure this isnt something mechanical with the engine causing it before assuming its the gauge itself. Car currently isnt running perfectly smooth at WOT (some sort of miss/surge crap) so dont know if this is related. All Im coming up with is that Im running too rich, but I have no idea why this has suddenly started up other than the entrance of much warmer weather (that could be it I guess ).
Okay whatcha guys think about the gauge deal?

 

[TurboRegal84]

When I had a VDO gauge it used to do that when I had a Leak in the Air Line Connetion.....Double check the line to be sure it is not leaking.

It might also explain why your car is running a bit rough due to the leaking boost line.

Where have you tapped for the source of Boost/Vacume?

 

[6SENSE]

I tapped at the back of the intake where the fpr and the map sensor/vac switch for factory idiot gauges get vac. I do have a couple spots on the boost gauge line where there was a crimp in the line, etc. and I cut it and connected with thin vac hose and wire ties. Connections are very tight, but I suppose there is the chance of leak. Only thing though, if I had a vaccum leak I would think that I would have a high BLM issue instead of a low one which Im going through now (110-115 at idle).

 

[irockwithdirt]

Does sound like the flutter of a vaccum leak?
I ran my entire plastic vac line inside a piece of rubber vac hose to avoid kinks or melting. Blends in under the hood to boot.

 

[6SENSE]

Went ahead and ran new line and fittings. Problem didnt go away. The motor at high rpm/boost is "fluttering" right along with the gauge (really sucks!; killing performance). Was thinking that it was too rich but have not been able to get it to go away. Then discovered bad module , swapped it and recent backfiring went away but the "fluttering" is still there . You think some sort of vac leak? Ive changed all vac lines (a number of times ). What do ya suggest?

Thanks