1990 Gen 1 SW20 Vent to Atmosphere?

[solitaire]

Hey

Put a k&n filter on my factory bov, blocked up the re-circulation hole in the air intake and started it up and it started coughing and spluttering... and definitely wont keep running...

I want a cool pfft noise! primarily because im still a big kid at heart! anyway to make this work? This cool chick in Repco Whangaparoa told me there was a way but it kinda flew over my head...

Does anyone know how to do this? it sounds like its running mega rich...

[Adamal]

Buy an aftermarket BOV.

If you don't know what you're doing when it comes to modding factory parts, then don't do it!

Sounds like its not doing its job properly and venting the built up pressure. That will cause compressor surging which will root your turbo

[Al]

Its on an mr2, use the stock BOV and run it like intended. You can't beat the performance of the stock BOV. The only one that comes close is the HKS SSQV.

You can fit other BOV's but the car will be slower than a car with the stock valve plumbed in.

[crnkin]

Yes but you didnt answer the question. I had the same problem on my mates wrx. We reset the ecu by disconnecting the battery for a few minutes then hooked it back up. I hate AFM. try it

[solitaire]

Yes but you didnt answer the question. I had the same problem on my mates wrx. We reset the ecu by disconnecting the battery for a few minutes then hooked it back up. I hate AFM. try it

On the button... yeah i dont want to replace the bov... i just want to vent it to asmos... i know the gen III's can vent fine... just cover up the hole on the intake where it is suppose to re-circulate and put a k&n on the end of the bov... Wldcrd has it on his fine...

But aparently the Gen 1's use afm which gets confused...

Ok ill try the battery thing... i read somewhere that the mr2 ecu's dont learn though?

[crnkin]

no idea, just try it i guess. Will be something simple

[slighty_sykotic]

I would say you somehow stuffed it up and the bov isnt sealing at idle/cruise.

So when you not under boost the bov is allowing air into the system that isnt being measured by the afm, causing it to run lean as hell and stall/die/cough.


Common on bov's that are vented to atmo AFTER the afm.

--Sykotic

EDIT:

Or prehaps your bov is stuffed? and when its plumbed in it doesnt matter if it's leaking cause of where its drawing air from (in relation to the afm).

[solitaire]

I would say you somehow stuffed it up and the bov isnt sealing at idle/cruise.

So when you not under boost the bov is allowing air into the system that isnt being measured by the afm, causing it to run lean as hell and stall/die/cough.


Common on bov's that are vented to atmo AFTER the afm.

--Sykotic

EDIT:

Or prehaps your bov is stuffed? and when its plumbed in it doesnt matter if it's leaking cause of where its drawing air from (in relation to the afm).

Hey, Thanks for all your replies

I dont think the Bov is stuffed... i swapped bov's with wildcard and there is no difference to it.... to my knowledge it has never been run for more than 60 seconds with the re-circ pipe off... Ben told me that there is an issue doing this with gen 1's, and that someone on here is bound to of made it work in the past...

If the bov was stuffed surely it would demonstrate issues at other times apart from when i have the re-circ pipe off? I dont think its the bov because i saw my bov working on wldcrd and it seemed to be doing its job from where i was sitting, its widely documented that doing the causes mixture issues... but aparently people have done it... so im just trying to find out if someone has done it... or i could be talking complete shit - the only thing im fairly sure of is since i have swapped out the bov it aint the bov....

[fivebob]

I would say you somehow stuffed it up and the bov isnt sealing at idle/cruise.

So when you not under boost the bov is allowing air into the system that isnt being measured by the afm, causing it to run lean as hell and stall/die/cough.


Common on bov's that are vented to atmo AFTER the afm.

--Sykotic

EDIT:

Or prehaps your bov is stuffed? and when its plumbed in it doesnt matter if it's leaking cause of where its drawing air from (in relation to the afm).

No, his bypass valve is functioning correctly and allowing air to bypass the turbo when the manifold is under vacuum. That's the way the stock valve works.

It's not designed to be vented to atmosphere so don't do it, if you must have that phssst sound then fit an aftermarket BOV or better still an ARC cold air box.

[solitaire]

I would say you somehow stuffed it up and the bov isnt sealing at idle/cruise.

So when you not under boost the bov is allowing air into the system that isnt being measured by the afm, causing it to run lean as hell and stall/die/cough.


Common on bov's that are vented to atmo AFTER the afm.

--Sykotic

EDIT:

Or prehaps your bov is stuffed? and when its plumbed in it doesnt matter if it's leaking cause of where its drawing air from (in relation to the afm).

No, his bypass valve is functioning correctly and allowing air to bypass the turbo when the manifold is under vacuum. That's the way the stock valve works.

It's not designed to be vented to atmosphere so don't do it, if you must have that phssst sound then fit an aftermarket BOV or better still an ARC cold air box.

OK... so just so i know what im talking about.... the stock ecu on a gen 1 cant handle it being vented to atmosphere? i know the stock bov can handle it because its currently doing it on a gen 3 mr2.... and the gen 2 bov off that gen 3 mr2 is currently on my car operating fine venting back into the intake as per factory... (they both appear identical... )

In summary the only way to do it with the stock bov on a gen 1 is an aftermarket ecu that can handle the air being vented to atmos rather than back in?

[fivebob]

OK... so just so i know what im talking about.... the stock ecu on a gen 1 cant handle it being vented to atmosphere? i know the stock bov can handle it because its currently doing it on a gen 3 mr2.... and the gen 2 bov off that gen 3 mr2 is currently on my car operating fine venting back into the intake as per factory... (they both appear identical... )

The ECU can't handle the unmetered air at idle, just because it works on a Gen III doesn't mean it's working properly. There is still unfiltered air being sucked through the bypass valve (note I called it a bypass valve, not a blow off valve)

In summary the only way to do it with the stock bov on a gen 1 is an aftermarket ecu that can handle the air being vented to atmos rather than back in?

Nope, while that would work it would still have unfiltered air entering the system. The only sensible way to have the phsssst sound with the stock BOV is by using an ARC cold air box, though with the AFM it's still muffled so adding a MAP based aftermarket ECU would be required to get that full boy racer effect.

[solitaire]

OK... so just so i know what im talking about.... the stock ecu on a gen 1 cant handle it being vented to atmosphere? i know the stock bov can handle it because its currently doing it on a gen 3 mr2.... and the gen 2 bov off that gen 3 mr2 is currently on my car operating fine venting back into the intake as per factory... (they both appear identical... )

The ECU can't handle the unmetered air at idle, just because it works on a Gen III doesn't mean it's working properly. There is still unfiltered air being sucked through the bypass valve (note I called it a bypass valve, not a blow off valve)

In summary the only way to do it with the stock bov on a gen 1 is an aftermarket ecu that can handle the air being vented to atmos rather than back in?

Nope, while that would work it would still have unfiltered air entering the system. The only sensible way to have the phsssst sound with the stock BOV is by using an ARC cold air box, though with the AFM it's still muffled so adding a MAP based aftermarket ECU would be required to get that full boy racer effect.

Understood, thanks man =)

[Akane]

do the check valve trick...... you'll get twice the rice, for 1/2 the price.

[FST4RD]

If you want to go cheap on the factory BOV you could do what I done in the past and my friend is using now.
I went to a gas fitting place and got a one way spring operated gas valve, it's the same diameter of the end of the BOV, got a piece of hose that fitted the end of the BOV and went on to the end of the valve, then blocked up the plumb back part of the cycle and there you go.
Cost me $20 for the valve and bout $2-3 for the hose, sounds awsome!!!
And it works a treat to, my friends car was running upwards of 18psi and it was fine (and if anyones heard bens turbo GTZ "blow off" you know what i mean by an awsome sound)

[solitaire]

do the check valve trick...... you'll get twice the rice, for 1/2 the price.

Ah, Ok.. (sorry bit ignorant) what does this involve?

[solitaire]

If you want to go cheap on the factory BOV you could do what I done in the past and my friend is using now.
I went to a gas fitting place and got a one way spring operated gas valve, it's the same diameter of the end of the BOV, got a piece of hose that fitted the end of the BOV and went on to the end of the valve, then blocked up the plumb back part of the cycle and there you go.
Cost me $20 for the valve and bout $2-3 for the hose, sounds awsome!!!
And it works a treat to, my friends car was running upwards of 18psi and it was fine (and if anyones heard bens turbo GTZ "blow off" you know what i mean by an awsome sound)

So the problem im having is that air is being sucked in the bov when the system is in vacum? is that correct?

thanks for the info

[FST4RD]

Yeah the problem with the factory BOV is that some of them dont close properly and car wont idle or run properly, I've used the one way gas valve one 3 of my cars now and my friend uses one on his 200 odd KW 4AGTE and it works a treat......

[solitaire]

so im loosing boost as well? cool advice... any suggestions on a gas fittings shop? (i dont actually know what one is... dumbass i know)

[FST4RD]

i only know of ones here in chch sorry

[solitaire]

ahh... ignorant aucklander.. sorry mate