So with my new found power/boost, I am double checking everything. My boost seems a bit low for the tune we put in it. I am testing the DVs now.




So I pressurized the f-pipe the 20 psi, and instanly the DVs are leaking air by. Is this test suitable to deem the DVs junk, or am I doing it incorrectly?

I also did the plunger test individually, and they both passed.
http://www.vaglinks.com/Docs/Misc/VA...rter_Valve.pdf

Any info would be great! Thanks everyone

 

Answered my own question. I did however find a new leak, well havent exactly found it yet. I can hear it behind the TB on the passenger side of the motor. I have removed the TB and am trying to pin point the leak. Its tough now that I cant pressurize the system. Any ideas?

 

as jeanmarc noted in your other thread. the likely culprit ( once other more obvious leak sources have been eliminated as "the" cause ) might be the #16 check valve as they are known to crack, create just enough of a boost leak to drive ya nuts, and is located just above the tb/plenum area. check the parts diagram for the #16 valve. this has been discussed a lot, but apparently not enough, as the leaks continue to confound people. this is more common than once? thought. but as the cars age, so does the plastic they made certain parts out of

its a wonder plenums haven't cracked.. "yet" lol

 

I did check all the #16s and they arent leaking. I am thinking its the Oring on the TB. I cleaned it and added some silicone. It held for a bit, then a leak developed again. I am going to make a lexan adapted to bolt on to the TB, so I can pressurize the intake without the Ypipe on. Hopefully Ill have better visibility.

 

Its probably the FPR vacuum line ... be careful....

 

Thanks Mark, I checked that as I replaced the FPR last week. Doesnt appear to be my leak. When I pressurize the system (at 20psi), it takes almost a full minute to drop below 20psi. Ill keep hunting. Im bound to find the issue causing low boost.

 

So how long does it take to drop to let's say 18 psi ? If it's within 30 seconds you have a minor leak and that would not cause your boost issues.
If you have a dirametric you should do a pull with proper values in 3rd gear so you can see what's going on. That's thag best way. There is nothing on the right side of the TB to leak. Unless the acrual oem intake that the TB is bolted too is leaking at the top where the 3 hoses are connected. There is a o ring and they leak sometimes.
Logs logs logs

 

You probably figured it out but for others who stumble upon this, you need to pressurize the small lines going into the top of the DVs along with the F-hose in order to properly check them.

 

It takes a couple minutes to bleed down to 18psi. I am almost certain its the TB Oring. I will order one on Monday. I dont have a durametric (yet), but will be getting one. I opted to put the car back together as I have a cruise/show tomorrow. I will strip it and get back on troubleshooting it later in the week.

I am tuned for 1.2 bar, and I am seeing 1.1 occasionally. My AP show 15.8psi max today. I figure eliminate EVERY leak, then move on to troubleshooting.

Thanks Mark!

 

Thanks Earl, I did figure it out. Appreciate the heads up.

 

unless you have after market Wgs on stock k16s you will never hit 1.2 bar sustained.. you will hit exactly the boost your hitting... not sure why you think you have a 1.2 bar file. If you have billets with Wgs then thats another story...
get a durametric before you drive yourself crazy... and if you just have oem k16s forget about getting 1.2 bar sustained...
markski

 

Ive got billets with Tial WG actuators

 

If your loosing 2 psi in a couple minutes the leak is not the issue. I guarantee you your looking in the wrong spot.
Either your wgs are set too low , or the n75 durty cycle is not set high enough. Don't think that a xxx tune will just run xxx amount of boost. I often tune remotely with various turbos and or wgs etc and it's not all the same. My basic 1.2 boost setting do not always hit the target etc. sometimes , more often then not its big leaks. But in your case it's all taken care of. Highly unlikely but sometimes a failing turbo will do that. I've see it.
So before you go any further, do a proper data log, send it to the tuner and have them adjust it. I bet your issues will go away. ( assuming your wgs are not set to 12 psi ).
Good luck
Markski

 

I need to test my WG pressure again. Im not certain they are properly adjusted. Ill also look into the n75 duty cycle.

Thanks again for taking your time to point me in the right direction. Its great to be part of a community where multiple people go out of their way to help fellow enthusiasts.

 

Just got back from the airport. I'll take a look for you Adam. We will figure it out

Thanks Markski!