Boost of 1 bar

[Christophski]

Hey guys my avant has been homefried (a while ago). What is it supposed to boost to? I fitted a boost gauge a while ago and have noticed it boosts to 1.2bar but just now I have taken it for a proper blat and it only hit 1.2 bar 3 or 4 times usually hitting 1bar and then stopping. I use the car daily and havent noticed any bad running. I fitted a cat by pass and ss 2.5 inch system in the summer and have noticed it smells of unburnt petrol alot.

I have also been running it on unleaded instead of optimax for the last few months but I was wondering if anyone has any Idea why it only boosted to 1.2bar a couple of times. Please dont say boost leak as I would have thought it would stop it boosting to 1.2 all the time and it hit that a few times just now.

Suggestions please??

[prj]

Boost leak.
You should hit 1.3-1.4 with ease.
And if you have a boost leak your car will run rich on boost.

It's the most common fault and is very easy to test.

[A80Avant]

a homefried should reach more than 1.4 i think (not sure though)

[Christophski]

Even with the car boosting to 1.2bar occasionally?
Does anyone have a bost leak test I could borrow? Also how do you do it? In based in Hemel Hempstead Hertfordshire

[prj]

You can't boost more than 1.4 and retain boost limiter on 2.5 bar map sensor.

[Christophski]

Could also explain the strong smell of fuel then

[prj]

Exactly my point.

[Christophski]

Cool. Is it easy to test or look for boost leaks?
Dont have a clue how to do that.

[prj]

Search the forum, it has been discussed many times.
Basically you plug the opening where the MAF is connected to the MAF-Turbo hose and also block off the breather exit in the same hose. Then using a compressor, you pump in air. Even at 0.5 bar pressure you should hear it hissing somewhere.

[Christophski]

Does this test the whole system or just a part of it?

[prj]

The whole system except the bypass and the breather pipes...
The breather pipes never see any boost, so if those leak, you'll just be running lean same as when you take off the oil cap on a running engine. A leaking bypass valve can be tested by blocking off the place where it connects to the maf-turbo hose and leaving the free end of the bypass valve unconnected.

[Christophski]

Cool cheers dude. Going to a mates workshop in a bit to try test some of these things if we can find stuff to bung the hoses

[prj]

You'll need to have a custom made part with a tire nipple inserted into it...
The outer diameter should match the MAF's outer diameter.

[Christophski]

Ok then in that case we will be doing as much of a check as I can until I get a kit for the car. Anyone got one I can borrow/ buy?

[andy broke it]

I have exactly the same problem, been suggested to check the recirc valve first as its easy. Hoping to check mine over christmas so if that is the problem il let you know.