My 6 bolt 1g with rebuilt
Motor only boosts 9-10 psi, 14b turbo before the rebuild it did 14-15. I did a boost leak and found none, everything is set up the same, 9-10 is with the bcs mod as well. So my
Thoughts are possibly a blown tirbo ?

Sounds like your just running wastegate pressure to me. That's what my car runs on wastegate pressure, MHI 16g, so same actuator as your turbo. I'd double check the solenoid setup and make sure the solenoid itself isnt bad.

If you want help, why don't you start by updating your profile with a current mod list.

How is the waste gate currently hooked up?

It's all stock...
Except for some internals and ors hooked up like it came stock

Pull the vacuum line off the waste gate actuator, and go for a drive. Do a little pull to see if you can get the turbo to make over 10psi. Don't go crazy, just see if the turbo will boost over what you've been seeing. Make sense?

Yeah I did and it it hit 15 psi just fine. So I'm just runnin off waste gate? How do I change that to how it was before

Well if u are hitting over 10 psi with out the wasyegaye connected, reconnect it and use a boost controller to dial in the boost u want.

What do you mean? If you want boost control, you need a way to control it. Hence, the name boost controller.

I don't have a clue why you saw 15psi before, and now you only see 10psi. There's zero information about your car to go from, so it's anybody's guess. Post some pictures, a diagram, or even a description of how your wastegate is hooked up.

Yeah, I know you already said it's hooked up like stock. So, like stock with it was at 15psi, or like stock at 10psi like it is now? Get my drift? Something changed, and it's impossible to tell what it was with the information you're putting forth. Go update your profile like I said before, even if your car is bone stock. You running a 14b, T25, what turbo before and after the rebuild? Put it in your profile, so nobody has to guess.

Half of the threads I respond to are helping people who don't take the time to do the little things like fill out their damn profile. It's extremely frustrating repeating the same shit over and over. Help people help you by doing your due diligence.

Same turbo before and after rebuild, the waste gate is hooked up with a t that connects to the dumptube nipple and the other goes the the bcs. and yes like stock it was at 14-15 psi . I did what you said and disconnected the wastegate and the turbo was able to achieve 15 psi and i got my hands on a boost controller, i thought it was a pos cause it wouldnt boost no matter what settings, so i switched the hoses back to how they were and i still have no boost? its like driving an n/a . I did a boost leak test yesterday and found nothing unless it happened today.

Do the simple mod of removing the bcs and just run the vac line from wastegate to j pipe nipple. This will let you run 1 or 2 more psi but still stock pressure. Do this and see what happens.

Yup did that, still 0 psi , very quit bov noise and dont even hear the turbo spool

When u remove the boost source and saw 15psi on the gauge did it spool like stock? Sound stock? Have you taken the intake off and inspected the compressor?

Sounds to me like you're running lower compression pistons.[DOUBLEPOST=1418100139][/DOUBLEPOST]Do you know what the compression ratio was of the pistons before and after the rebuild.

The compressor is fine, I've inspected it. and they are oem style pistons with rings. Today it was 10 psi and now after trying to install mbc at 0

Have you checked the turbo for play just remove intake pipe and wiggle it up and down and in and out.If it has a lot of play its toast.

What about the things I asked u? Give the turbo a general inspection,wastegate arm, the clip, compressor. Also, what are u using for vaccum line even though a collapsed kine wouldn't cause this. Try using new line. Make sure its the good stuff. This is an odd situation if everything you are reporting diagnostics wise is true and correct..

Your blow off valve is staying stuck open when your driving.

Dafuq are all of you saying?

If the turbo builds boost just fine with the WG disconnected, that probably means the BOV, turbo, and all the other shit mentioned is operating as it should. If suddenly, when you put a vacuum line on the turbo it fails to build boost, I'd think that indicates your WG is seeing more boost than it should.

You need to examine how the WG is hooked up. After you confirm the vacuum line routing to the WG and boost controller is correct, set the controller to the desired boost level. I'm not sure why this is so complicated.

Install the boost controller like so: http://www.dsmtuners.com/threads/best-way-to-install-a-mbc.237982/

Do that, and if you still have issues, post back here.

Yea but if everything his saying is correct and he knows what he's talking about, he had it setup correctly.

Just in case some of you missed it.

GST with PSI said:

Dafuq are all of you saying?

If the turbo builds boost just fine with the WG disconnected, that probably means the BOV, turbo, and all the other sh** mentioned is operating as it should. If suddenly, when you put a vacuum line on the turbo it fails to build boost, I'd think that indicates your WG is seeing more boost than it should.

You need to examine how the WG is hooked up. After you confirm the vacuum line routing to the WG and boost controller is correct, set the controller to the desired boost level. I'm not sure why this is so complicated.

Install the boost controller like so: http://www.dsmtuners.com/threads/best-way-to-install-a-mbc.237982/

Do that, and if you still have issues, post back here.

Click to expand...

Sounds like your wastegate actuator is acting funny. How does it boost up to 9-10 psi? If its hitting 9-10 psi quickly like it should then stops making more then your waste gate is staying shut like it should but then opening too quickly. If its taking forever to get to 9-10 psi but then finally gets there and doesnt make more then your wastegate is probably slightly stuck open all the time, and may need to shim the wastegate. All signs point to the wastegate. As said above re-examine all the easy stuff such as vac lines being nice and tight and hooked up correctly.

I guess you didn't read it right. He has apparently done the appropriate diagnostics and hooked it up right and still got 0psi then 0 psi with a boost controller. Then disconnected it all and had boost again. It almost doesn't seem possible. But he still hasn't answered what me and another guy asked if it spooled and sounded normal when he sees 16psi

Well by disconnecting the wastegate essentially what you're doing is keeping the wastegate from opening at all and allowing the turbo to free boost without any limiting control. If when he puts vacuem back to the wastegate it starts to prematurely open OR stay partially all the time, hence bleeding off boost, i would assume either he is not hooking up these lines right or he has a bad actuator. If he's bleeding pressure out the BOV then once again its due most likely to the vac lines not being connected properly. Seems to me he was making boost before he messed with the lines again to install the MBC.

He claims he is not making boost with a line from the turbo outlet straight to the accuator then makes at least 15psi with the source running to the wasyegate. That is odd. I asked him twice to inspect the arm and clip and stuff but hr hasn't answered that stuff. Its an odd situation.

Perhaps the vacuum line was cracked before the rebuild and this line was replaced? This could cause a slight overboost situation.

I am assuming this is an aftermarket gauge as well. If it was the factory gauge, a boost leak will cause it to read high.