Hesitation!

[newsh]

Mine was leaking at the clamp where it connects to the ECU so I just cut a half inch off the pipe (thats why I suggested you do this). You could just have split in the line somewhere, this will act as a kind of one way valve, opening under pressure and closing under vacuum.. You need to have a look at the back of the inlet manifold where all the small pipes connect and look for oil mist, a boost leak will bring a little bit of oil vapour with it thanks to the breather system The line to theECU should connect to a hard plastic line on the bukhead.
This is pretty sure to be your screeching noise IMO.

[newsh]

[newsh]

As you can see, a leak in that line also messes up what the FPR sees, no wonder it makes it run rough

[newsh]

Edit: Also check by the ECU. On my car Carly managed to kick the end of the recirc valve on the AC and I was left with a vacuum line hanging down by the ECU. Could they have been accidentally swapped over? I know it sounds daft but sometimes it is the silly little things that cause the problem.

Ben

Well done Ben!! Steve has just left my place with a smile and a car that goes Pipes were swapped down by ECU.

We may still have a small leak but it was no weather for more testing and I have to drive to Wales now Boost gauge was showing 1.3Bar dropping to 1 Bar steady to redline. I would think it could boost more but not sure what Paul has set it up to do.
Wastegate has never been tampered with so probably stock spring and screw position in there.

[stevieyid]

Yep big thanks to John for spotting it. The green ECU line was plugged into a valve of some sort that sits behind the glovebox. There wasa black vacume pipe thatwas plugged into the ECU hence the vacume readings all the time. Anyone know what the hose could be for? John thought it could be for the Air Con?

[stevieyid]

Anyone know what the vac line could be that i have now plugged? Just wondering if this responsible for my current excessive vacum

[s2avant]

That valve is for the AC recirc.

Ben

[Rusty]

It doesn't take much to make a big difference, I had a tiny leak and it cost me about 30bhp

[stevieyid]

It doesn't take much to make a big difference, I had a tiny leak and it cost me about 30bhp

A tiny boost leak? We done a pressure test and really could not find anything. As i said though the PCV leaked although this would not affect the boost. I think a catch tank is my next upgrade

[newsh]

Anyone know what the vac line could be that i have now plugged? Just wondering if this responsible for my current excessive vacum

How do you mean excessive vacuum?

[stevieyid]

How do you mean excessive vacuum?

On start up i seems to have around minus 0.7 to minus 0.8. When driving i drop the clutch and the vacume will go to below minus 1 bar.

[newsh]

That's absolutely fine and is a healthy sign

[A80Avant]

you think? how come most of the rest S2/RS2 engines idle at -0.4/0.5bar and on overrun -0.8? Are ours unhealthy?

[stevieyid]

So is 0.8 bar normal then and in fact healthy? Could be a relief if it is