DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum banner

My Bov Is Not Blowing Off! Help!

4449 Views 24 Replies 10 Participants Last post by  ProjectSoloGear
allow me to clarify...I put on an HKS SSQV on my car earlier this week, started her up, and I was shocked when it sounded just like my old one(crushed 1G BOV). upon further inspection, I realized, I had never been blowing out the BOV at all, rather it sounds like its coming out of my intake..!? Im out of ideas...spent the weekend looking for a vaccuum leak, removed my manual boost controller and reconnected the stock boost solenoid and all lines...so the vaccuum line from the manifold is going straight to the bov...and still the same. the sound changed though, its not as loud/long...still comin from the same spot. could the wastegate have anything to do with it? Ive been contemplating as to how that would even come into play, I could be wrong though...
at the end of my rope here, any help would be greatly appreciated.
1 - 20 of 25 Posts
The wastegate shouldn't have any effect on the bov operation.

When you say it is blowing off out of the intake do you mean that is where you here the sound coming from? If so that is where the sound is hear on bovs that return to the intake.

If the bov was not opening you would hear the painful sounds of compressor surge. When you do hear it making noise does it sound like compressor surge?
yes, the sound is coming out of the intake. its not the bov cause the UICP I have relocates the BOV higher up, away from the intake. and its going to atmos., not recirc. yes, yes, I know, thats bad. I have the recirc fitting as soon as I figure out what the problem is its going on.

its a fluttering I hear...Ive never actually heard comp surge but everyone Ive had look at it, thats what theyre describing it as.
Bov not opening is most likely a vacum line issue.
thats what I figured, but what other lines have I missed? Ive check the one going from the manifold to the bov...and any others having to do with the turbocharger system...maybe its something Im overlooking...
Try to set the screw on the back all the way out, the more the screw is out the less surge and easy the BOV will open
my screw is practically almost all the way out...and from what ive been reading up on that has nothing to do with adjusting the BOV...what kind of vacuum should I be pulling from the manifold?
The Super Sequential is notorious for falling apart, did you buy it used? I remember reading a quote from an HKS rep somewhere where he made the point that he wished they had never put the adjustment bolt in the back. He said that "if" it needed adjustment , it should be no more than 1/2 to 1 turn at the very most. It is suppodaly very eay to back the screw out too much and the internals fall apart.
I have never repaired one myself but have 2 friends that have been successful in doing so.
yes I did buy it used, but the thing is its the same problem as with the stock one. I put the stock BOV back on, its the same thing. daaah if its broke imma be
the sound you hear is compresser surge, once the line on my BOV came off and thats exactly what happened, are you positive you hooked the BOV up to the right vacuum line?
and yes HKS was foolish to put the screw in the back, an HKS rep told me that the screw doesnt even do anything to adjust it.... :confused:
dont know what to tell you, look up where all the vacuum lines are supposed to go.
good luck
I had to take my HKS ssqv apart to fix it. The adjustment bolt on the back of the bov definately adjusts the spring tension. The bolt pushes against a plate that compresses the spring. Backing the bolt out will help with compressor surge. Mine is backed out all the way and I still get compressor surge.

Try pulling the vacuum line off while the car is idling and check if the hose is getting vacuum.
I wrote a few things about the HKS SSQBOV on the Albany message forum which I will paste here. I think it will help explain more about the anatomy of this seemingly complicated piece of work.

ProjectSoloGear said:
If you guys ever used this HKS bov before or read user feedback on this item on forums, you'll know there's a whole lot of trouble with them if used on a DSM. This BOV is actually designed for high boost applications cars such as the Toyota Supras. First of all, if you don't fully boost the car over 15psi, this mother will compression surge BIG TIME. Second of all, if you have them vented to the atmosphere, the car will most likely stall at the light. This is because of the following things

1)The SSQBOV springs are set for holding boost beyond 20 psi all the way up to 30 psi or more. Although it's a two stage venting bov, the lower psi stage (primary valve) only vents with a diameter of about 1/2 inch which does not allow for much air to go out. It is also the only "pull" type bov which insures that it never gets stuck and always locks the air tight regardless of how much boost you're running. Only when the diaphragm senses a throttle release (boost building in the intake line) will it pull open the vents.

2) Venting to the atmosphere is always bad bad bad. Unless you have a GM MAFT or something alike, our stock fuel mapping does not allow registered air to leave the system...that is unless you want to replace functionality with attention grabber. The S-AFC does account for Air Deceleration Fuel Tuning, but guess what, it doesn't work on DSM's.
ProjectSoloGear said:
What happens to venting to the atmosphere is you end up having a sudden PIG RICH fuel mixture which goes to drown out your engine.

There are fixes to make the BOV work with our DSM's and I've done them all. I've ran this BOV ever since I gotten it and I do not have a CEL or compression surge issues. More on that in a bit.

The first test drive didn't go too bad though. I loved the way HKS sounded. At low boost level the venting sounds something like Wooffshhhhh and at high boost level it has the combination of that and a loud PSSSSSSssshhhhhh thanks to the three blade whistle fins. BTW, these fins are replaceable to give different sounds.
ProjectSoloGear said:

So how did I fix it?

Let's address the compression surge issues first. If you take a look at the diagram above, you can see that the set-screw affects the spring rate of the valves. The more you screw it in, the higher the spring rate gets, and vise versa. Even if you have the screw backed out to its last thread, the bov will still surge. So...are we out of options? Nope, not yet.

Obviously I did this way down the road since in "story time" I'm still an amature in car mechanics. But I'll include it here since it's pertinent.

So there are screws in the back of the SSQBOV

which are removeable with hex wrenches. Be real careful when you get down to the last few nuts and bolts because that thing is spring loaded and can take your eye out.

Once you have it apart, check out the mechanisms within. There's a few ways to go about doing this. Either you have to find a spring that is about the same size but have a lesser spring rate, OR you can do what I did which is finding tiny zip ties
and clamp the spring down just a little bit from its neutral state. I had to experiement with it a bit to insure that there is enough spring force to close off the diaphragm after it vents. Or else the flow of air through the valve will keep the bov vented even after you get back on the gas pedal. Bad!
reaxion said:
yes I did buy it used, but the thing is its the same problem as with the stock one. I put the stock BOV back on, its the same thing. daaah if its broke imma be
The adjustment screw won't do anything for you if your stock bov won't even work. Fix the car with the stock bov and then put on the HKS.

One thing that didn't seem clear from your writing is, how do you know it doesn't vent? Since you said you vent to the atm, do you feel air coming out when you rev in neutral?

nothing was coming out of the valve, no. sorry I didnt include that, thought I was pretty thorough with the breakdown...

here we go...

stock boost solenoid

one line of the tee going to the comp. pipe...

other tee to the wastegate...

source from the intake manifold going directly to the BOV...

in. mani. vac source going directly to the BOV

these 2 lines, there not pulling vac. at least I dont think. I pulled them off with the engine running, didnt really notice a hesitation or change in idle.

engine bay shot

and there it is...any help would be much appreciated my fellow tuners.
See less See more
Humm..can you tee off the boost source for the MBC and hook it up to the BOV and see if that works. Atleast you can tell if the BOV is functioning correctly.

Humm..can you tee off the boost source for the MBC and hook it up to the BOV and see if that works. Atleast you can tell if the BOV is functioning correctly.

Id have to put the MBC back on...its running off the stock boost solenoid right now. I dont have an aftermarket boost gauge on at the time. youre talking about tee'ing off from the wastegate to the BOV? the way I had it set up before, the MBC had 2 lines. the line from the wastegate to the MBC, and from the MBC the line is tee'd back to the intake manifold, which is also the line to the BOV. am I understanding you correctly?
I just had to chime in and say that the hks blowoff valve with different baldes looks so good I'm about to drool....exactly what sounds do they make...could someone post a audio clip???
I forgot to mention, the 1g bov I originally had on the car? I crushed it too far down and thats why it wasnt working. is it normal for a car not to blow off at idle, but it will under load? cause I hear 2 different flutters, one at neutral and one under load. I think its actually working, from what Ive been reading the flutter is normal (low boost) I just need to adjust for the valve for higher boost.
1 - 20 of 25 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.