boost gauge doesn't go passed 0
 

my 88 rx7 turboII has a problem the boost gauge moves to zero and then doesn't go passed.and my emgine runs realy rough above 5500 rpm please help!! thankz

those are two diffrent proplems. You need to make sure your gauge is connected properly and if your engine is running rough do a compression check. If the engine checks out do a full tune up this includes fuel filter.

the gauge is well connected and thankz for the tune up tip

you might have a massive boost leak also...check all your couplers and shit.