defective bov?

[androo007]

Hi chaps,

Some help really needed please! Thought I'd stick the one and only modification to the MR2 on today, a hks style bov bought from here advertised as working just fine.

Installed the bov (blanked off big pipe, ran new pipe from IM to bov.

However, I've noticed a few things:

It's not a tight psssshhhht more of a whaaaaaaffftttttttttttttttt that lasts forever unless it's flat out.

I can hear air rushing on throttle - again, shouldn't it be closed until throttle release?

The valve inside opens when on throttle - surely this isn't normal behaviour?

Only driven 10 miles but obviously I don't want to risk anything. So, first question, can a defective bov mess with AFRs on the Rev 3?

Can get a video if needs be, i'm pretty confident it's defective but after confirmation from the experts.

[Ryan S]

Valve should be closed on throttle, it's a pull type valve so the more boost, the tighter it seals. The noise will depend on what insert you have in it. If it is opening on throttle then it's not operating as it should, get a refund 👍

[androo007]

Yeah, that's exactly as it's doing. Ok thanks very much, I'll whip it back off the car. Seems it's destined to stay standard....although I'm happy with that!

[Peter Gidden]

Toyota OEM - 1
Cheap paddy field knock off "HKS style" - 0

Now there's a surprise.

I'd be sending it straight back to the seller.

[androo007]

Sounds about right, thanks Peter. I don't normally skimp out.... ever. (This was the last pennies from spending a decent amount on servicing and general replacement of worn parts) but still pretty gutted. Will request refund from seller. Thanks!

[GreddyMR2]

Please help!

Not creating another topic I will ask here.

I have OEM blow off valve which I suppose could be defective.

Here is the issue. Sometimes, when I push a bit of throttle (not boosting, but a bit more than cruising), the sound appears like a boost leak or something. It's starting to blow the air somewhere, but when I push more, let's say holding vacuum around 0, that sound is gone.
The sound appears only when vacuum is around -20 (normal cruising vacuum is around -35).

Could it be the bov? Of the VTV valve? I suspect VTV as well as I can blow to one side freely, but also can blow a litlle bit (very hardly) to another side. As I know it should work only in one side, no?

[Ryan S]

Please help!

Not creating another topic I will ask here.

I have OEM blow off valve which I suppose could be defective.

Here is the issue. Sometimes, when I push a bit of throttle (not boosting, but a bit more than cruising), the sound appears like a boost leak or something. It's starting to blow the air somewhere, but when I push more, let's say holding vacuum around 0, that sound is gone.
The sound appears only when vacuum is around -20 (normal cruising vacuum is around -35).

Could it be the bov? Of the VTV valve? I suspect VTV as well as I can blow to one side freely, but also can blow a litlle bit (very hardly) to another side. As I know it should work only in one side, no?

I could be miles off but this is from personal experience, and this is only relating to vent to atmos. While on half throttle (or thereabouts) sometimes I could make the valve open, it's like there's not enough pressure to keep it closed and not enough vacuum to open it fully, i had this with a stock valve and an apexi valve. however, recircing, you shouldn't have this problem. if it's set to recirc then the intake should theoretically suck the valve closed.

[GreddyMR2]

Please help!

Not creating another topic I will ask here.

I have OEM blow off valve which I suppose could be defective.

Here is the issue. Sometimes, when I push a bit of throttle (not boosting, but a bit more than cruising), the sound appears like a boost leak or something. It's starting to blow the air somewhere, but when I push more, let's say holding vacuum around 0, that sound is gone.
The sound appears only when vacuum is around -20 (normal cruising vacuum is around -35).

Could it be the bov? Of the VTV valve? I suspect VTV as well as I can blow to one side freely, but also can blow a litlle bit (very hardly) to another side. As I know it should work only in one side, no?

I could be miles off but this is from personal experience, and this is only relating to vent to atmos. While on half throttle (or thereabouts) sometimes I could make the valve open, it's like there's not enough pressure to keep it closed and not enough vacuum to open it fully, i had this with a stock valve and an apexi valve. however, recircing, you shouldn't have this problem. if it's set to recirc then the intake should theoretically suck the valve closed.

It's recirculating... And the sound appears not always.

By the way, maybe it could be related to my other problem that I can't find... My vacuum on idle is around -40 when it was to be around -55 before. And the engine sounds like with aftermarket cams. But this problem is only on idle.

[Ryan S]

Please help!

Not creating another topic I will ask here.

I have OEM blow off valve which I suppose could be defective.

Here is the issue. Sometimes, when I push a bit of throttle (not boosting, but a bit more than cruising), the sound appears like a boost leak or something. It's starting to blow the air somewhere, but when I push more, let's say holding vacuum around 0, that sound is gone.
The sound appears only when vacuum is around -20 (normal cruising vacuum is around -35).

Could it be the bov? Of the VTV valve? I suspect VTV as well as I can blow to one side freely, but also can blow a litlle bit (very hardly) to another side. As I know it should work only in one side, no?

I could be miles off but this is from personal experience, and this is only relating to vent to atmos. While on half throttle (or thereabouts) sometimes I could make the valve open, it's like there's not enough pressure to keep it closed and not enough vacuum to open it fully, i had this with a stock valve and an apexi valve. however, recircing, you shouldn't have this problem. if it's set to recirc then the intake should theoretically suck the valve closed.

It's recirculating... And the sound appears not always.

By the way, maybe it could be related to my other problem that I can't find... My vacuum on idle is around -40 when it was to be around -55 before. And the engine sounds like with aftermarket cams. But this problem is only on idle.

hmmmmm.....I'm getting dejavu here, I'm sure I read on here somebody else having a similar problem with the vacuum reading, i'm sure their cam timing was out by a tooth??? I also think Mr Gidden diagnosed it so he may be able to tell you.

[GreddyMR2]

It was me!

But appearently timing belt is fitted corectly. And all vacuum hoses seem connected well and have no leaks. I think of doing boost leak now.

[Ryan S]

It was me!

But appearently timing belt is fitted corectly. And all vacuum hoses seem connected well and have no leaks. I think of doing boost leak now.

oh, hahaha, has your idle been adjusted??

[GreddyMR2]

No, nothing was adjusted. The guy just replaced piston rings, that's it. And from that time vacuum screwed.

[Driftlimits Performance]

Unlike any others the stock dv will only close once mani has reached positive pressure.

[Ryan S]

Unlike any others the stock dv will only close once mani has reached positive pressure.

ah, that's right, i mind using one to vent to atmos and it stayed open when you lifted off, wouldn't close until you put your foot down again.

[glen n]

This was my bov which I'm sure was a replica. Worked fine throughout my ownership of the car and was fine on the day it was removed. May have been damaged in the post or may have just broken. I'll have a look at it when I get it back.

[Gullzter]

Weird, your car ran perfect Glen

[Ryan S]

to be absolutely fair here, I've used plenty of the replicas, and despite what Peter thinks of them, I've never had one fail on me (i've said this many time on here) I have had genuine HKS valves fail that's why I always buy the replicas, I'd rather have 1 year from a replica than 2 years from a genuine. my replica has been on the car for ages now and is completely fine.

[Baker]

Androoooo, What car do you have, rev1/2 or 3+?

It sounds like it's been incorrectly installed, or your car is not producing enough boost - does it hit full boost?

[androo007]

Hi Baker, It's a Rev 3 - tbf i dont see how it can be installed incorrectly - Bolted in with no leaks, and a 4mm hose from IM outlet to the BOV.

Looking at the BOV end on - the circle ring that has SSQV BOV text (I think usually purple when new) is off-centre and wonky to one side..... which makes me think the postie may have been a bit too heavy handed somewhere - i poked by finger in and it doesn't rattle around at all though.