Possible Air Leak, Please Help

[GunMetalR33]

Hi,

I was driving back from work the other day and my car was running fine. I was giving a a good burst from time to time then started to notice that the power was progressivly decreasing. By the time I got home I could not boost it over 5psi and at the point it runs realy rich...

I know its rich due to the state of the plugs when I pulled them out to do a compression test, which seemed fine as well (all within 10%).

Things I have done to fix it are:

1) re-fitted all intake piping after the Afm and before the throttle body, there were no obvious leaks.

2) replaced the Z32 AFM with a mates and it made no difference.

I was thinking it could be:

1) crank angle sensor?

2) plenum gasket?

3) maybe a pin hole in the cooler, I have checked and cant see anything?

Any suggestions would be great, I am thinking air leak but its very hard to determine where it might be???

[GunMetalR33]

Anyone had probs like this before?

[Omurru]

check all of your vacuam/boost lines, make sure they are all still connected properley.

[GunMetalR33]

good point, will give it a look over.

[GTR32GUS]

soapy water can be handy when looking for leaks , put some on and look for bubbles

[GunMetalR33]

soapy water can be handy when looking for leaks , put some on and look for bubbles

arh, nice idea. The problem that I have is that it only seems to have problems above 0 psi, so I guess it needs a bit of boost to open the leak or something...

[Primordial]

Did you end up sorting this out? I had a very similar problem, and it's turned out to be a plenum gasket for me.

I could actually feel the air rushing out through the giant hole.. I could still get a heap of boost into it though, but it was making a rushing air sound out the side of the plenum when on boost.

[GunMetalR33]

Yea, it was an air leak in one of the hoses that goes from the turbo out of the engine bay