I am new to the forum and the rb25 so I am at a point where I really need help. I have a 95 S14 with a 93 rb25det everything stock except 80mm TB, greddy intake manifold, and front mount inercooler and 255 walbro fuel pump. I did all the work myself but I can't seem to figure out the boost problem. When I give it gas its fine but when boost starts to build it leans out and starts surging I get blacck smoke so I assume too much fuel not enough air. I have checked for leaks and come up empty handed. I know with the provided info there is prob 100 possible solutions but just help me know where to start I can provide pics and more info if needed. Please help. Someone has to have done this swap

Moved to RB forum.

Black smoke = too rich.

I think you might have a bad MAF.