I have read all of the threads that post vacuum diagrams and such, just trying to see if anyone can narrow down the possibilities based on my specific symptoms. In first gear: if a launch at high rpm's then it will bost up to about 5-6. if i dont lauch then it wont boost. If i shift from second to third at high rpm's then it wont boost. If i shift to third at low rpm's and then get on it from about 2k then it will bost up to about 7 and then drop off to about five. The exact same syptoms from third to fourth and fourth to fifth. My turbos are only 15k miles old, so its not them, no oil leaks or smoke. Any help is greatly appreciated. Im thinking that i have a boost leak somewhere do to the fact when i shift at high rpm's it doesn't boost. Thanks alot.

 

somebody has to have some ideas! please any help?

 

I guess a half hour is too long to wait?

 

Sorry I just got it and really want it to boost right.

 

Definitely start with inspecting for boost leaks. Gotta take the couplers off the car to do it.

Then I'd take off the pressure tank and inspect the check valves that go to the pressure tank and vacuum tank. Test or just replace them.

Dave

 

It doesn't sound like a boost leak to me, as the problem isn't linear. It does sound like a sequential control issue.

As Dave said, check your check valves/pressure tank. Start inspecting all of the hoses going into the turbo control actuator/turbo pre-control actuator and into the solenoids themselves. I had the same issue once, which turned out to be a slightly loose hose causing one of the actuatotors to work intermittently.

Cliffs: read the sequential turbo faq and do some preliminary troubleshooting.

Btw Dave, I have to tip my hat to you. You always respond to people's sequential turbo issues. I lost interest in posting the same stuff over and over again years ago.

 

I agree, but it's never time wasted to start with looking for leaks. Especially because in many cases once the control problem is fixed, you still don't get 10psi but nobody thinks to go back and look for a leak.

BTW jet I would have responded the first time but I literally didn't have time to finish reading your post and think about it.

Dave

 

thanks alot guys, i have read all of the troubleshooting posts about this problem! I justs helps to narrow the possibilities down, there are a lot of things to check for. any body else have any ideas?

 

Sounds like you have more than one problem. First is to check for your boost pills and/or make sure you have the right line plugged in for the Wastegate solenoid. Either of those will basically limit your overall boost to about 7 PSI.

Next, it sounds like your Turbo Control isn't functioning properly. There are several components to it and you need to start checking them. Look at the troubleshooting guides for those topics and start getting them hands dirty.

 

awesome thanks to all very much.