Boost issue

[dyl33]

Hello, so I've developed a issue where im only holding 6psi. Boost is controlled via hks-evcs.

Cars mostly stock.Nistune,tbe,12psi.

Usually if i plant the throttle i hit 12 psi straight away and holds. At the moment it hits 10-12psi visually on the boost gauge but instantly drops to 5.8-6psi.

Cars seems to drive fine off boost. Ive gone over the ic piping vac lines all seem ok. Idles fine.

If anyone has an idea or could be of some help it would be greatly appreciated.

Thanks

Edited January 15, 2019 by dyl33

[GTSBoy]

Direct connect the boost source to the wastegate and see what happens then.  Will tell you if the boost controller is good or is the cause of the problem.  There are a whole lot of things that can be wrong, from problematic boost control solenoid valve, to broken linkage in the wasetgate flapper.  Impossible to internet diagnose, beyond the above pointers for places to start looking.

[dyl33]

2 hours ago, GTSBoy said:

Direct connect the boost source to the wastegate and see what happens then.  Will tell you if the boost controller is good or is the cause of the problem.  There are a whole lot of things that can be wrong, from problematic boost control solenoid valve, to broken linkage in the wasetgate flapper.  Impossible to internet diagnose, beyond the above pointers for places to start looking.

No worries mate ill give that ago when i get a chance tomorrow.

We are starting to lean towards boost controller fault. Boost control solenoid valve not working properly. resulting in running wastegate pressure.

[GTSBoy]

Yuh, could be sticky, could be electrically broken (ie, moves when you put power on it, but then overheats and faults, etc).

[dyl33]

She ran perfect wastegate pressure. So i say b/c is rooted. Thanks you gtsboy!

Just to clarify if it were a wastegate issue it would boost to infinity. And if it was a Bov issue it would dump the pressure prematurely?

[GTSBoy]

No.  A wastegate can either stick open or closed or anything in between, plus a bunch of other unwanted behaviours.  So you can either have uncontrolled boost, or barely any boost or any combination of symptoms.  A BOV doesn't usually fail such that it just opens up and dumps boost.  They do leak, and if it's bad enough you might lose a few pounds from the top end.

[dyl33]

Ok go it thanks gtsboy!