Broken breather thing

rpruen · Post by **rpruen** » Mon Feb 26, 2007 10:13 pm

pol wrote:Thanks rpruen... So when under vacuum, the valve allows flow into the manifold from both the oil sep and by the turbo inlet at the sme time / mix? And under boost does not flow in the other direction back to the oil sep and the inlet?

Under boost the flow is blocked from the manifold, but is still allowed to the turbo inlet.

So all you need is a 'T' and a non return valve in the pipe to the manifold. Stick the 'T' on top of the seperator 'can' and then connect one end to the NRV, the other to the pipe from the turbo inlet.

That would remove the plastic nastyness completly.

Richard

pol · Post by **pol** » Mon Feb 26, 2007 10:33 pm

I might just do that!

Soooo, under boost, the vapours are drawn through the turbo, and under vacuum, drawn through the manifold yah?

So how about the valve next to it?! Connects to from manifold to idle regulator and has a vacuum line attached?

Hopefully i'll have another go at the weekend.

pol

crispy-d · Post by **crispy-d** » Tue Feb 27, 2007 12:29 am

Ah right, so in fact the valve allows air through to the manifold at idle anyway! I thought all air taken in at idle went only through the idle valve, so it can control it. So changing the NRV wouldn't fix the high idling problem. Hmm, well I hope it's just the broken recirc valve then! Off to Wilcos then to get myself a NRV. What a waste of Â£5.99!!

Thanks bbf & Richard. Hope you get yours fixed, Pol.

Crispin

rpruen · Post by **rpruen** » Tue Feb 27, 2007 6:23 am

pol wrote:I might just do that!

Soooo, under boost, the vapours are drawn through the turbo, and under vacuum, drawn through the manifold yah?

Yep that's it.

pol wrote: So how about the valve next to it?! Connects to from manifold to idle regulator and has a vacuum line attached?

Again it stops air going back from the manifold to the turbo inlet through the idle valve. I replaced mine with a recirc valve (the VW type). It seems to work ok so far.

Richard

pol · Post by **pol** » Tue Feb 27, 2007 10:31 am

You have a recirc valve as normally used for turbo re-circ in place of the smaller re-circ? Interesting.... Is the VW one a weaker spring / smaller or anything?

Crispy, my high idles in the past have always been a vacuum leak or idle valve. Find a replacement with the right code on it for a start i reckon... My inlet manifold gasket was my biggest leak which isnt the easiest to find. The nuts on the manifold studs seemed to have worked loose over time... I'm still tempted by the little filters myself so not giving up on the idea! Give it a go... If it works... You could then maybe just have the line from the turbo inlet running to the manifold with the NRV in place and the Oil sep with the filter on top? Valves and things eh?!

Cheers

pol

crispy-d · Post by **crispy-d** » Tue Feb 27, 2007 2:31 pm

Well, I've got the filter on there for now, so I'll let you know how it goes. If the valve on the idle valve is acting as a recirc valve would, then it looks as tho it works back to front, in that the boost pressure acts towards the diaphram, rather than to the side of it (does that makes sense?)

Mine only idles high when it's warm. Or rather (as I've turned the idle down now) it idles to low when cold, then fine when it's warm. I will check the manifold bolts again, but I'm thinking although resistance seems fine, it may be the idle valve. It's spotlessly clean, but doesn't affect idle at all when it's unplugged, or when the throttle is moved past the 'switch off' point.

Rachel · Post by **Rachel** » Tue Feb 27, 2007 7:56 pm

I know that somewhere in this thread is the answer to my low cold start idle....I sense I'm close, but I'm also confused

rpruen · Post by **rpruen** » Tue Feb 27, 2007 8:59 pm

pol wrote:You have a recirc valve as normally used for turbo re-circ in place of the smaller re-circ? Interesting.... Is the VW one a weaker spring / smaller or anything?

The recirc valve is the same as the Volvo one, but has metal parts on the end of the diaphram. The spring is if anything a bit stronger than the volvo one. It works ok and is about 500 times stronger than the one that is standard for the idle valve pipe.

You will have to adapt the pipework to fit the 25mm valve, but a few adapters should sort it. I replaced all the pipework with 25mm on my car anyway, so the recirc valve was easy to fit.

Richard

pol · Post by **pol** » Tue Feb 27, 2007 10:17 pm

Sounds good, did you re-tap connectors into the manifold for larger pipes or just reduced / increased via adapters?

Got any pictures of your engine bay at the moment rpruen? Sounds very interesting!

po

crispy-d · Post by **crispy-d** » Wed Feb 28, 2007 6:48 pm

Fitted my new 710N valve today, replacing my original which had a huge tear round the edge of the diaphram!

Just as everyone else that's done the same thing has said - it now runs so much better, I didn't quite believe it made that much difference. It's so much smoother now, and also idles much better. No more juddering when closing the throttle suddenly after boost, which is nice. What's more, it doesn't 'pop' anymore, which is even better! Thought that was a fuel problem, so changing the dump valve has cured most of the problems I had! Not too mention it's a fair bit more responsive, and it now boosts right to the end of the red

Back to topic - my engine's also working very well (smoothly and responsively) with the breather filter fitted. Don't know how it affects emissions, but it seems to run a bit better.

martinholmesuk · Post by **martinholmesuk** » Wed Feb 28, 2007 6:59 pm

@ Rachel, I'm almost certain this is the cause of the cold bad idle. It's the only thing left that I never changed (i never had a spare) Vader ditched it a looooong time ago and like i said in my posts back in 2005 yes it's a bad idle cause. (I don't mean the n710 as i changed it already)

martinholmesuk · Post by **martinholmesuk** » Wed Feb 28, 2007 7:13 pm

N710 is the black valve (I paid Â£21 or near that a few days ago)
the brown valve is a non-return valve to replace the 480 crap valve.

rpruen · Post by **rpruen** » Wed Feb 28, 2007 7:26 pm

pol wrote:Sounds good, did you re-tap connectors into the manifold for larger pipes or just reduced / increased via adapters?

Got any pictures of your engine bay at the moment rpruen? Sounds very interesting!

po

Yep there are pictures I posted a link to the directory full of pictures... It's here if you want to have a look

http://www.richard.pruen.btinternet.co. ... ercharger/

Not sure you can see all that much, as I moved things about. The idle valve lives under the supercharger. Everything is 25mm, the conections to the idle valve have a smaller diameter bit of tube inside the 25mm to act as an adapter. The idle valve air now enters the manifold on the end opposite the throttle body where there is normaly a core plug type thing. The normal hole for the idle valve pipe is tapped and plugged as it would foul the supercharger.

Richard

pol · Post by **pol** » Wed Feb 28, 2007 10:07 pm

Fair bit going on in there! Wow,!

I spotted the new outlet on the manifold where the plug normally is, and there's an FSE over there... Oh and a big supercharger... You've fitted braids over the standard intercooler / turbo hoses, good plan! Makes me spending a few hundred on new suspension soon seem like pennies..

Couldnt find any good non return valves in focus tonight... In fact everytime i've been there I think i've come out empty handed. Crap shop!

Crispy, what size little filter thingy did you get? Did you plug the other connections off?

That was another thought I had about the oil breather, is it not bad for these gasses to be drawn through the turbo inlet after the MAF, as in, it won't be metered?

pol

crispy-d · Post by **crispy-d** » Wed Feb 28, 2007 10:47 pm

I'm not actually sure. I just bought the first one I saw and whacked it on (and have thrown away the packet now). But I just went out to check, and the 'can' connector is 12-13mm in diameter.

I did plug both the pipes, otherwise charged air will be wasted back to the inlet of the turbo, as if the recirc valve was constantly open. Don't want to waste any boost

I too have looked for NRVs but had no luck. Martin has obviously found a decent one. Where'd that come from then?

Richard will no doubt explain the positioning of the breather pipes, but my guess is that the mass flow of vapours being drawn from the sump will be negligable compared to the intake of air. Surely it's just evapourated oil (and maybe a bit of fuel vapour).

rpruen · Post by **rpruen** » Wed Feb 28, 2007 10:51 pm

pol wrote:Fair bit going on in there! Wow,!

I spotted the new outlet on the manifold where the plug normally is, and there's an FSE over there... Oh and a big supercharger... You've fitted braids over the standard intercooler / turbo hoses, good plan! Makes me spending a few hundred on new suspension soon seem like pennies..

There is a lot there alright. That's what has taken so long, most of it was fiddly and chalanging to make, or expensive to buy.

The FSE is going soon. The rising rate part doesn't help at all, a flat response regulator will be much better. It was just hanging about so got fitted as the pressure is adjustable.

pol wrote: That was another thought I had about the oil breather, is it not bad for these gasses to be drawn through the turbo inlet after the MAF, as in, it won't be metered?

Not sure about that... The blowby from the piston rings has already been metered through the MAF, so it's just going round the engine again. Any upset from the small flow should be easily compensated for by closed loop oxygen control anyway.

At idle the air is drawn in through the MAF, and into the vent valve, then on to the manifold. The actual proportion of blowby gasses is resonably small compared to the amount of fresh air. If the turbo inlet pipe was before the MAF it would draw in unmetered air.

If you fit a filter then you would need to block off the two pipes to stop air geting in unmetered. Also the car will in theory not pass an MOT, as closed crankcase ventilation is required. Most MOT staitions may not check, but some could.

Richard

pol · Post by **pol** » Thu Mar 01, 2007 9:12 am

Ok, that makes sense.

Non-return valves are also known as check valves by the way.

There are a couple on the bay but don't know if theyd be any good...

pol

Rachel · Post by **Rachel** » Thu Mar 01, 2007 6:27 pm

@ Martin....yeah thanks, I ordered a new one the other day, so fingers crossed - will let you know.

martinholmesuk · Post by **martinholmesuk** » Thu Mar 01, 2007 9:46 pm

@ Rachel, The other idea I came up with is the valve off the idle valve. If you need one your welcome to my good looking one. (i spend vast amounts of time working out this things when driving)

I can feel when a 480 is not running right... The 480 whisperer

I also been buying parts.

Cam belt / recirc valve / water pump (mech)

Rachel · Post by **Rachel** » Thu Mar 01, 2007 11:43 pm

@Martin....Thats the part I have just ordered. I have Lucy's oil seperator valve also.