HELP i had just changed the oil and was out on the highway and was in 3rd gear then shifted into 4th then the car suddenly only boosted to .8 bar (guessing wategate pressure) no vacum lines seem to be disconnected and car has done it once before but acted normal again after several restarts of the motor and a 100 mi or so. after this i assumed it was a fail same mode. Now i tried restarting and unplugging the battery and it still has the same problem with boosting to wastegate pressure.

 

what kind of boost controller are you using?

 

its a manual, i think hallman
hoses are all hooked up to the bc as well as wastegate

 

it is a manual hallman

 

if it is a hallman, one of two things has happened.

1) the ball is stuck, or something is keeping it from seating.
2)something is wrong with the spring


both issues are easy to fix. to do it, unthread the bottom nipple. be careful though, because the ball is really small and easy to drop. it will be hiding on the other side of the nipple once you take it off. once the ball is out, make sure the back side of the nipple is clean, and there is a good surface for the ball to seat into. make sure the ball is clean as well. next get the spring out of the hallman. it is right behind the ball. you might have to tip the body of the boost controller down to get the spring out... or reach in there with a pick. once the spring is out, make sure it looks normal. reassemble it, spring, ball, nipple. and try boosting again.

 

Hey I'm having the same problem on my evo 8, did you end up fixing the issue?