boost cutting before max need troubleshooting help

[JakeD97gsx]

hello all so i just recent got my 1997 GSX and am relatively new to the seen. my father owns an autobody shop and i do all my own work on all my vehicles so i know my way around a car but this is my first boosted vehicle. my first car was a 97 talon esi auto with just the plain 420a in it.

what my question for you guys and what i haven't been able to find much on is when i make boost in the lower gears 2nd especially it kicks out b4 it reaches its max. its not a miss fire i know that for sure and the car has been tuned and has a electronic boost control valve set for 18psi on a stock t25 i pulled the intake off and check the turbo and the bearings are fine. im just wondering if anyone has any ideas what may be happening.

 

[bryanwheat]

Do a boost leak test. You likely have a boost leak which is causing fuel cut especially at 18 psi.

 

[JakeD97gsx]

the vent lines on the tank were plugged, causing a vacuum on the tank and back pressure on the pump