If I had a boost leak?

[Dred]

I haven't gotten around to doing a leak test, but my question is the following.
If I had a boost leak, would I alway get powerloss, or could it vary? My car "sometimes" chokes (at 3.5-4Kish RPM), and sometimes runs very good.

Could this be a fuel pump problem?

 

[DSM90AWD]

A boost leak will have a progeressively worse impact at greater boost levels/rpms..etc.

Imagine blowing up a balloon with a hole in it trying to get it to a certain size. The bigger you try to go (more boost), the more air leaks out and the harder you (turbo) have to work to get it to that desired size

Another ill-effect is that since the ECU reads airflow via the MAS which is before the turbo. It then injects the appropriate amount of fuel based on an internal fuel table.

Since less air is actually reaching the cyls than is read by the ECU you will run much richer AFRs than normal often leading to fouled plugs and overall crappy performance

 

[psychlow]

I haven't gotten around to doing a leak test, but my question is the following.
If I had a boost leak, would I alway get powerloss, or could it vary? My car "sometimes" chokes (at 3.5-4Kish RPM), and sometimes runs very good.

Boost leaks rarely cause intermittent problems - it'll usually be always cause a decrease in performance that gets worse as you apply more boost.

You seem to be having problems around peak torque, where cylinder pressures are the highest. I'd suspect that your problems would be fuel delivery related without having more information about the problem. It could be the pump, but that would usually get worse as RPMs and boost got higher as well.

 

[toojung2die]

Has the fuel filter ever been replaced? A clogged fuel filter will cause the mixture to lean out when you're getting on it.

 

[Dred]

Yah i replaced the fuil filter not too long ago.
It feels like it's running lean sometimes at the RPM range. What's weird, is that it's not always there, sometimes, like I said, it runs awesome.

 

[oldman]

Imagine blowing up a balloon with a hole in it trying to get it to a certain size. The bigger you try to go (more boost), the more air leaks out and the harder you (turbo) have to work to get it to that desired size

Take this very seriously. My blown 16g is now a decorative piece on my desk, right next to it is my old leak tester.

I have some questions for the thread starter, your profile indicated stock, is that accurate? Do you have a boost gauge? If so, what psi are you running? Free mods? Tell us everything. In the mean time, keep from full throttle until you figure this out.