BOV not working - 1G-GTE

[Z2TT]

Hello, I have a Toyota Soarer GZ20 1989 Model, with a 1G-GTE, Automatic.

I have just noticed that it has a BOV that is not working.
The BOV is located in the pipe that leads upto the intake manifold.
From the Pipe comes the BOV.

What I have noticed is

1. There is a little hose about 1cm diameter that comes from the BOV and that goes into the intake manifold, it had fallen off,
putting it back on made the car idle better

2. The Outlet of the BOV had some kind of paper membrane that seems to be ripped.

3. The BOV has some kind of Nut on it for adjusting something maybe.

The problem is I never hear the BOV release any air, I never hear the sound when I drive the car.
What should I do to try fix this problem?

As for testing, would it work if I rev the car heaps in Neutral then release the gas pedal or would I have to drive it?

Thanks,

[Stock_22]

is it venting to atmosphere, or is it plumbed back in??

[Z2TT]

It Is supposed to vent to the atmosphere when its working properly I think, I dont know much about BOV's, It has a Trumpet like outlet that has no hose connected to it so I guess it vents to atmosphere.

Thanks.

[whatthe?]

The pipe coming from the intake plenum is absolutely necessary for the BOV to work. It lets the BOV know when there's a pressure differential (ie; when youre off the gas) so it can vent the compressed air in the intake tract.

Not sure about any paper membrane at the outlet, but you wont hear very much by revving the car in neutral anyway, as the car wont make much boost unless the engine is under load (driving). The nut on top may be for adjusting BOV (when it vents) or it may just hold it together depending on brand. If it's an atmo type and not a plumb back then it's aftermarket

[Z2TT]

Yeah my problem is the BOV might be stuck and never opens, or maybe opens too early and doesnt hold the pressure maybe thats why I cant hear it. Its a BLITZ BOV.

The small hose that goes from the BOV to the intake manifold is not held by any sort of clamp where the BOV is, should I put a clamp there, maybe pressure might leak from there?

As for the BOV what can I try to do? Adjust that nut?

[whatthe?]

Does the car make boost when youre driving? What sort of noise do you hear when you change gears or get off the gas? Do you have an airbox or a pod?

[Z2TT]

The Car is an automatic, When I let off the gas I dont hear any distinctive noise. I have a pod filter. When I drive the car I can hear the turbo's boosting up and I can really feel the car speed up faster under boost.

[whatthe?]

no boost gauge? It would be helpful to know if the car is dropping oiff boost when youre up it. Even a car with no BOV, no airbox and a pod filter will make a fairly audible "cha-cha-cha" noise due to reversion if it's making and holding decent boost

If the pipe is off the BOV though, that's the first thing I'd fix and go for a drive. Hose clamp both ends if need be

[whatthe?]

Oh, and BTW it idles better when you connect the hose to the BOV because the 1G is an AFM engine and the BOV hose causes a vacuum leak when it isnt connected. The AFM (big ugly thing with wires coming out of it near your pod) tells the ecu to fuel according to the air it see coming into the intake. A vacuum leak at the manifold sucks more air in at idle than the AFM is allowing for meaning you dont have enough fuel to idle well. Conversely under boost that pipe will cause a boost leak which will add to your current BOV problem

[chrisrundell69]

bov might be seized also, my old sard one was, just needed to pull it apart and clean off all corrosion and muck that was inside. try everything else first before you go pulling it apart

[Z2TT]

Yeah I also have a front mount intercooler, just thought I might let you know. As for that little hose I might hunt down some clamps and put them on.

Other than that anything I should try?

[whatthe?]

One thing at a time, the hose first . Knowing what boost is doing would also be mightily useful, boost gauge is a simple thing if you don't already have one. Do you know how boost is currently controlled?

[Z2TT]

How boost is controlled? You mean do I have a boost controller installed? I dont have one.

[whatthe?]

Yes, that's what i meant. if there isn't a boost controller or bleed valve then it's likely that the car is set as factory with a hose running from turbo compressor to wastegate actuator. This may explain why you dont hear any reversion when you get off the gas if the BOV isnt working. The 7 odd psi the turbos make stock wont make it noisy. Does it have the factory exhaust? A decent aftermarket exhaust system tends to raise the boost levels a factory setup makes

[Z2TT]

The owner who i bought it off said its got a 2.5" exhuast, I think its a cat back.

I think its 10 PSI for my turbo's, because I am pretty sure I got the Gen 3 1G-GTE.
But yes I do have a small hose branching off the main pipe and running to the wastegate actuators, that hasnt been modified no bleed valve etc.