Blow Off Valve will not go off Help!

Ok like i said the BOV will not go off! Getting Surge
My setup
1990 Mk3
Aristo 2JZGTE
Driftmotion Intercooler kit
Knock Off HKS SSQV

When i first did the swap the swap the BOV worked fine for the first week. Vacuum hose it Tee'd into the same line as the power steering vacuum line. So after it stopped working i figured something went wrong with it. (A)So i replaced it with a brand new one and hooked it up the same way. It worked for the first few minutes of the drive and then i started getting compressor surge again. I dont think this matters but a did see a little bit of oil in the charge pipes.

Plan (B) i thought maybe it wasnt reading vacuum right so i put it on its own dedicated vacuum line it still will not go off!!!!

What are my options to get this thing to work im getting really discouraged.
 

destrux

Active Member
May 19, 2010
1,183
10
38
PA
You would be wrong.

My knockoff bov didn't even work out of the box. It's not an HKS though, it's a greddy type-s knock off. I had to take it apart and machine major internal parts that they copied wrong, and then a month later I needed to put a real greddy diaphragm in it. Five years later it still works fine though.

Anyway, try taking it apart to see what's not right. Usually there's just a burr or an o-ring was cut or put on wrong, or they forgot to tighten a screw inside or something. I don't use HKS BOV's so I don't know how they look inside, so that's all the advice I can give.
 
destrux;1774947 said:
You would be wrong.

My knockoff bov didn't even work out of the box. It's not an HKS though, it's a greddy type-s knock off. I had to take it apart and machine major internal parts that they copied wrong, and then a month later I needed to put a real greddy diaphragm in it. Five years later it still works fine though.

Anyway, try taking it apart to see what's not right. Usually there's just a burr or an o-ring was cut or put on wrong, or they forgot to tighten a screw inside or something. I don't use HKS BOV's so I don't know how they look inside, so that's all the advice I can give.


yea i will never use HKS style ever again. There way of mounting with that stupid snap ring is ridiculous lol. Why cant they just use screws like everyone else
 

Poodles

I play with fire
Jul 22, 2006
16,757
0
0
42
Fort Worth, TX
zSP3CTERz;1774824 said:
Ok like i said the BOV will not go off! Getting Surge
My setup
1990 Mk3
Aristo 2JZGTE
Driftmotion Intercooler kit
Knock Off HKS SSQV

When i first did the swap the swap the BOV worked fine for the first week. Vacuum hose it Tee'd into the same line as the power steering vacuum line. So after it stopped working i figured something went wrong with it. (A)So i replaced it with a brand new one and hooked it up the same way. It worked for the first few minutes of the drive and then i started getting compressor surge again. I dont think this matters but a did see a little bit of oil in the charge pipes.

Plan (B) i thought maybe it wasnt reading vacuum right so i put it on its own dedicated vacuum line it still will not go off!!!!

What are my options to get this thing to work im getting really discouraged.

Wait, what? Why aren't you using the factory vacuum source for the BOV?
 

IBoughtASupra

New Member
Mar 10, 2009
4,455
0
0
Queens, NY
^ That.

You need a vacuum source that is after the throttle body plate, meaning towards the inside of the motor. Also known as a manifold vacuum source.

Anything that is infront of the throttle body plate before, where the intercooler pipe is will make your blow off operate incorrectly.

As the throttle body plate closes, the pressure after the throttle might still be present, but behind the plate towards the motor, you will always have vacuum when it is closed which any blow off valve needs to operate correctly.
 

87M-GTE

Slow
Sep 12, 2007
1,705
0
0
Milwaukee WI
Its a combination of that ^ and the shitty china knock off HKS bov. The "shell" is identical to the real HKS bov, however the internals are complete garbage.

I bought the DM FMIC kit, and took apart the fake bov out of curiosity... Weak spring, cheap thin rubber diaphram.. waste of time to even bother running it.
 

xzeror

Active Member
Oct 18, 2009
1,356
1
36
Miramar, FL
MDCmotorsports;1775410 said:
Blah blah blah i cheaped ass out on a major mechanical item for a turbocharged engine and i cant believe this Chinese pos doesnt work....

GET A REAL BOV

+1