Hey guys.
I finally got my coil installed, and fix all the oil leak.
however, there had been another problem risen.
my boost!
second gear about 4,000 rpm, my boost just drops dramatically to 0.3 and slowly peaks back up to 0.5 and holds it there.
before 4,000, it's got enough pressure to hit up to 0.7-0.8.
and whenever after 4,000rpm (when the boost is dropping), I can hear this weird phh noise (sounds like something's holding it, and won't let it go), and boost is just hesitating.
what's you guys' opinions?
there had been two major opinions on this issue.
1. boost leak, leaking vacuum lines, check valves
2. stock solenoids. (to get a boost kit)

 

Start with searching for the boost leak. Always start with that.