Why am I overboosting w/14b

[BOBS90TURBO]

I just installed a MBC and I have it turned down all the way and I am still boosting at 20+ psi (my gauge only goes to 20) in 1st to 3rd gears, I am boosting around 17 to 18 in 4th and 5th gears. Is there any way I can turn my boost down to 15 or 16 psi with my waste gate spring and if so does anyone know how or what to do. I have a stock waste gate system, I have free mods and K&N filter/hacked can. Also the car is a 90 with a manual with a 14b. Thanks

 

[RipperXX]

What kind of MBC is it?

And are you sure you hooked it up right?

 

[BOBS90TURBO]

My MBC is a homemade style I bought off Ebay for $30 bucks, If I did have it on backwards what would happen?

 

[candela]

Exactly what its doing...
Make sure its not leaking, pressure test it. if its leaking elsewhere it could be bleeding on the wastegate line and hence your situation. $30 is silly for a homemade, you can buy very nice quality ones for $10 more. If you need more help PM me...