boost leak

[prove_it]

I was curious about boost leaks and was wondering how big a hole would have to be if I can't boost past 5 lbs on a completely stock intake piping, sensor and turbo.

I've even unplugged the wastegate and could only push 5 lbs.

I will do a leak test, but I was wondering how big of a leak I am looking for. Vacuum line sized? or pin hole sized?

 

[turbowop]

I once had a boost leak that was caused by a loose ic/hose clamp. It would start up and idle and cruise fine but as soon as I got into it it would only build 10psi and fall on its face. Maybe something to look out for.

 

[vr4play]

I would check the wastegate flapper and make sure its not stuck open. If you only get 5 psi that would be a massive leak and it should idle funny at the least.

 

Yes I would think it would be a serious leak - or stuck open wastegate.
What happens when you get to 5 psi - does it cough choke buck or just not boost past 5.
If it runs rough (cough choke) then it would be boost leak.
If it runs fine just not boostong past 5 then it is probably on the wastegate end (Or BOV opening at 5 psi)

 

[prove_it]

I cleaned and retighting all clamps on the IC pipes. Resealed the throttle body. Here's the whole story:

I used this built engine and turbo on 1284 for three thousand miles and it would hit 10lbs at half throttle in fifth gear on the interstate at 3200 rpms. It was always in boost. Always. I had a custom built front mount for it using 2.5 inch pipe. Then after 3k miles it got totalled and I found 715, so I transplanted the engine. When I did I used the stock IC pipe and IC because I built the Front mount for non AC and now I have AC. Ever since the first start it's never pushed more than 5 lbs.

In the accident the turbo didn't get hit, don't think always.
She runs great while driving and cruising. Good fuel trims, good ratios. I'll get no smoke and it pulls good for no boost then just won't go past 5 lbs.
However, it struggles to idle. No surge or high idle, but when I push the clutch in and come to a stop it dips to 400 rpm the picks up. ONly when I fully stop will it idle at 900. perfectly.

NO obvious leaks. Nothing jumps out. I swapped my ISC and no difference.

I have DSMLINK V3 and everything looks good there.

Frustrated at this point.