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Intermittent no.2 problems


Keith C

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I did search, but either I missed it or I was searching badly.

 

I have a UK 95TT6 with 120k on the clock, and I'm having an intermittent problem with no.2 turbo.

 

My mods are very light; full decat and a bleed valve, no more. I never have problems with no.1, and when no.2 engages I should see a spike up to 1.4bar before gently tailing off to about 1.2bar as revs increase.

 

However, on occasion I will only spike to about 1bar, and boost will drop to about 0.7bar as revs increase. The car also does not feel as though it is accelerating as quickly.

 

It does seem to be going through the 'transition' as boost drops off momentarily at the usual place, it's just a lottery as to whether no.2 will join the party.

 

I find it very difficult to reliably reproduce - I have had 200 mile journeys with no problems, or 20 mile ones without no.2.

 

Does anyone have any suggestions as to where to start looking on this, as I'm also concerned about doing damage to no.1?

 

Thanks in advance for any help.

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I've got this on problem at the moment, I think it could be one of the VSV's that control the turbo. IIRC there are 4, but I don't know which one is knackered on mine.

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There have been a few discussions around this in the past. I know my previous cars have done it occasionally, but I just ignored it. Others couldnt do that and so swapped to single turbos when they couldnt find the solution.

 

IanC is good with the stock turbos, perhaps ask him for his views.

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Guys, I recently had a similar issue. It turned out to be the vac pipe that goes from the T piece at the rear of all the plumbing, about 3 inches long if I remember correctly.

 

The pipe was still attached but was loose and obviously not sealing correctly. Replacing it solved the issue.

 

To begin with I would intermittently lose boost from tubby 2 and ended up with it not boosting at all.

 

Will get a picture tomorrow if you want.

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I had similar issue, was caused by previous owner incorrectly installing the boost controler.

 

Check that the sequential system is plumbed correctly as stock. With the exeption og the boost controller.

 

Maybe worth removing the boost controller and checking if it still does it.

 

There is a section in the FAQ which shows the stock siquential setup :-)

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It's a bleed valve, not a full EBC - and I've already tried winding it back in so it's as if it wasn't there, and it still does it.

 

The bleed valve has also been fitted 'as-in' for about 10 years now, nor have I changed anything for about 8 years, so I'm reasonably confident it's a fault/leak somewhere as opposed to a misconfiguration.

 

The pics would be great - I can then get in there and check things out :)

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I had a very similar problem

 

I was only bpu, so 0.7 and 1.1-1.2 but sometimes i'd only get to 0.8 on 2nd turbo.

 

It was the VSV on the top left of the picture with the 3 blue pipes.

 

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc6/188797_10150125202999820_509114819_6259823_6092668_n.jpg

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