S13 SR20det Boost lag, bad gas mileage

[boost86]

So I got this car from a guy I know recently, and he wasn't able to fix this problem. The car builds boost very slowly and gets horrible fuel mileage.

The motor is an s13 sr20det with a brand new s15 turbo, megan exhaust manifold, pbm front mount, etc.

When I go wide open throttle, the car is laggy and slow. On the boost gauge, the boost builds very slowly upward. It's like 3 lbs.. 4 lbs .. 5.. 6.. 7.. 8.. 9.. 10..

So once I reach 10 lbs of boost, the car obviously feels much faster, but I'm at like 6000+ rpm's to get to it. Not to mention, the car gets terrible fuel mileage. I burnt through over an 1/8th of a tank in 15 minutes. The car misfires very slightly at idle.



Possibly problems:
-Timing?
-TPS?
-WG Actuator?

I'm pretty lost, all I'm looking for is some suggestions where to start. The previous owner claimed the timing was set at 15 degrees, but I'm going to check it out anyways.