BOV not working - 1G-GTE

[whatthe?]

Ok, well, first thing is to make sure the hose from the BOV to the plenum stays attached and see if that makes a difference. If it doesnt and it still feels like it's boosting then next thing is to install a boost gauge to see what boost is doing under load or pull apart/replace the BOV

[Z2TT]

Well once I put the hose back on with no clamp it has not come off since, should I still put a clamp on?

[whatthe?]

If it stays on and your idle has improved then that's probably not the issue. Knowing if it holds boost through the rev range is the next logical step, you'll need a gauge for this. Either that or replace the BOV and hope that the new one works!

[whatthe?]

Hey, have you got any pics of how it's installed? Has it worked at all since youve owned the car? Maybe a dumbass installed it wrong?

[Z2TT]

I'll try to get some pictures tommorow of the BOV and how its installed. It has never worked since I owned the car. But it looks to me as its installed correctly, The intercooler pipe has been cut another pipe has been fitted there with the BOV attached.

[whatthe?]

Well, as long as it's on the inlet tract between compressor and plenum with a hose to the plenum it cant be too wrong. Guess it's replace/rebuild and/or gauge time for you...

One more thing, try loosening the bolt on top and turning the top half of the assembly all the way anti-clockwise. maybe it's done up too tight to vent at 10psi (long-shot here)

[Koffee-Black]

I have the same issue. Just installed a blitz BOV yesterday, and does not work...im going to try and adjust the nut at top, and see if that helps...arrgh this is what happens when you buy used!

[Z2TT]

Today I pulled apart the BOV, and it does not look like its siezed. I tried to push the valve and it works. I found that there is a bolt that you can turn to adjust the spring tension. It is currently set at the minimum amount of tension, even with that the sping is pretty tense.
I clamped the hose that comes from the BOV to the plenum with a little hose clamp. Then put it all back together, and still it does not vent. I revved it to the redline, turbo's were boosting and the BOV did not seem to leak at all, just stayed closed, when I let off the throttle, it does not vent.

[woggin]

the motor WILL NOT boost in neutral!!!! it has to be under load!!! it will not hit boost....it will be on vacuum the whole time.....how is it wired up.....are you sure everything is put in correctly!!! and you havent got it hooked up the wrong way round! (would that make a difference??)

i have my BOV hooked up with my GFB MBC!! (i.e. on the same line)

[4SFED]

the motor WILL NOT boost in neutral!!!! it has to be under load!!! it will not hit boost....it will be on vacuum the whole time.....how is it wired up.....are you sure everything is put in correctly!!! and you havent got it hooked up the wrong way round! (would that make a difference??)

i have my BOV hooked up with my GFB MBC!! (i.e. on the same line)

This isnt always correct. I can make about 10psi in neutral and with a free rev then backoff the BOV will crack open no problems. I can even get my external wastegate to crack and vent onto the ground with some big revs in neutral (16psi wastegate spring).

Obviously this is on a pretty modified motor with a nice roller bearing turbo, but i am pretty sure that even a factory car can make some boost in neutral.

Being an auto, there shouldn't be any reason that you cant put it in drive and give it some throttle whilst standing on the brake to get it under load and make even a small amount of boost. This would give you an easy way to see if the BOV is popping open at the right times or not.

The vacuum hose that hangs off the back of your valve, if you leave it attached to your BOV and disconnect the other end, stick it in your mouth and suck. What happens? You shoudnt be able to suck air through it at all (ie: it should be sealed). if you can your valve is knackered (very possible). If it is ok, then we need to look elsewhere.

[Z2TT]

Yeah my car makes boost in Neutral, and since then I've driven it too and no venting. Maybe the spring is too loose and the pressure leaks, or maybe the spring on my BOV is just too tight to vent at 10 PSI.

I'll try sucking through the vacuum hose when I get some time.

Here is a picture of how its set up, I'm pretty sure its correct.

[woggin]

This isnt always correct. I can make about 10psi in neutral and with a free rev then backoff the BOV will crack open no problems. I can even get my external wastegate to crack and vent onto the ground with some big revs in neutral (16psi wastegate spring).

Obviously this is on a pretty modified motor with a nice roller bearing turbo, but i am pretty sure that even a factory car can make some boost in neutral.

Being an auto, there shouldn't be any reason that you cant put it in drive and give it some throttle whilst standing on the brake to get it under load and make even a small amount of boost. This would give you an easy way to see if the BOV is popping open at the right times or not.

The vacuum hose that hangs off the back of your valve, if you leave it attached to your BOV and disconnect the other end, stick it in your mouth and suck. What happens? You shoudnt be able to suck air through it at all (ie: it should be sealed). if you can your valve is knackered (very possible). If it is ok, then we need to look elsewhere.

really, i have tried it many times and only seen vacuum!!! although on the supra the intakes flutters in neutral!!! but that isnt building positive boost!!! nor does it have a bov...thats just the backpressure!

[Z2TT]

Today while driving I think I heard the BOV vent, it was a very subtle "pschh chee" noise.

Only things i've done is cut 2 holes in the intake pipe the pod filter covers so it can suck more air in, as I noticed it was very restricted, and made the nipple on the BOV flanged so the vacuum hose stays on better.

Still not 100% sure if that was the BOV I heard.

[turbo4agte]

Could possibly be surge noise. It sounds similar to a muffled BOV. I'd try and give you advice but you haven't posted any real pictures.

Most of the time BOVs are leaking at idle, so I dont see how you can build boost at idle either. But then again I've never had a car with a ball bearing turbo, or twin turbo engine either, so I cant say for sure. Also, how do you know they are boosting at idle? gauge?

Only suggestion I can make at this point is keep turning the spring nut on the top. See what happens.

[Z2TT]

Boosting at idle? When did I say they were boosting at idle?

Yes it might be compressor surge, since the BOV isn't venting it could well be compressor surge.

What do you need pictures of? Basically setup just like I drew it in the diagram

Edit :

Fixed. After tightening the nut on the BOV a bit, i can now hear a good but subtle tsssss noise.