I'm having trouble creating boost. I had to put my car to stock to pass smog and now I can't get it to make more than 3 to 4 psi. I'm running a star stage II setup which has the mark vii wastegate that controls boost between 2-4 psi. I have a ball and spring manual boost controller that is installed between the line feed from the turbo to the wastegate.

I took the boost controller apart and every thing looked fine so I reinstalled it. I have checked for vacuum leaks, leaks in the intercooler, plugged air filter,.... and haven't found anything wrong.

What's odd is that the boost stays at roughly 3 psi, .20 bars according to my dtt, regardless of how I adjust the boost controller, which leads me to believe that the manual controller can only hold 3 psi and the wastegate is controlling the boost. When I had the boost controller off I blew threw one end and adjusted it tell it shutoff to verify that it was working. All that I can think of is that the spring has failed and can't hold more then 3-4 psi.


Any thoughts on possible causes? Anyone live in Bakersfield and have a boost controller I could borrow for a run?

Thanks for the help.

Not to attack your intelligence, but have you checked for a boost leak on your I/C piping, BOV, etc.

Yea, I checked that with no luck. I guess there are two things I can try. One is install a new boost controller and see if that resolves the issue. Or, connect my boost gauge off of the turbo instead of the manifold and see what boost pressures I get. If I do get higher boost off the turbo than in the manifold, except the normal psi drop through the fmic, then I must have a leak in the ic piping that I haven't found.

Did you check by pressurizing the IC piping system? That's really the only way you can find every single leak.

I visually inspected the tubing to make sure all the connections were good and I listened for leaks by reving the engine in neutral. The only problems is the turbo doesn't produce much boost with out a load. I think connecting a boost gauge to the turbo might be the best way to determine if there is a leak.

The best way would be to build yourself a tester. You can find info on it by searching, but basicly get some PVC pipe a cap and a tire valve. Put the cap on the length of pipe drill a hole for the tire valve. Install the valve and clamp the pipe in place of your air filter. Then pressurize it with an air compressor and listen for the whistle. Be very careful not to over pressureize it though, you don't need 100PSI in there...

No, you need to build a boost leak tester and pressurize the whole intake system. Look on vfaq.com, or search here on the board, for instuctions on how to do this.

Originally posted by DarkOne
No, you need to build a boost leak tester and pressurize the whole intake system. Look on vfaq.com, or search here on the board, for instuctions on how to do this.

Just to make sure I'm not crazy, that is exactly what I described right Dino?

Yeah.

Originally posted by TNemesis
I visually inspected the tubing to make sure all the connections were good and I listened for leaks by reving the engine in neutral

ROFL. Your not pressurizing a damn thing by doing that :) Boost leak testing involves adding air through your turbo inlet w/ the help of a fitting you will make/borrow and a air compressor.

Just an update. I found that the rubber coupler that connects the ic piping with the turbo wasn't fully sealing. Thanks for all the input everyone.