yah if uve got a needle bouncing up on down its probably a vacume leak for sure, check all ur hoses going to the intake manifold make sure they are all connected correctly also look for cracks or leaks, if its not that u may have a leak around the connecting surface of the intake manifold, does it do this all the time? or just on occasion? if u've got lots of parts do a quick compression check on the cylinders make sure ur valves arent stuck open cuz that can cause funkiness, but i had something like that and didnt find out that one of the hoses off my intake manifold had blown off as well as the erg hose was blown off cuz my intake had pulled stuff out of where it should have been when it shifted around