turbo

[Coreybrieseman]

Just replaced my 1st and 2nd turbo on my 95 gt legacy first turbo is not boosting as hard as it should 2nd is any ideas y 1st isn't boosting

[Rosssub]

 Coreybrieseman said:

Just replaced my 1st and 2nd turbo on my 95 gt legacy. First turbo is not boosting as hard as it should, 2nd is. Any ideas why the 1st isn't boosting

Did the primary (1st) turbo feel ok before it went in? Shaft spinning ok with minimal play. What psi is it getting to?

Make sure the primary turbo-WG vac hoses and T-piece went back in the right way around. In this pic the paint dot shows where the restrictor pill should be:

[Coreybrieseman]

Yip turbo was all good and restrictor pill that could be y then you think have a manual boost tap on it pill could have come out

[Rosssub]

 Coreybrieseman said:

Yip turbo was all good and restrictor pill, that could be why then you think? I have a manual boost tap on it and the pill could have come out

Have you got a boost gauge fitted?

How have you got the boost tap set up? The factory T-piece and restrictor pill come out when fitting a boost tap.

[Coreybrieseman]

Yip have boost gauge ready 0 then when second turbo kicks in goes to 10 have a boost tap set up way it should be pill is on the waste gate side is that right

[Coreybrieseman]

Had pill round wrong way will change it around and take it for a drive see if that works if not what else could it be

[Rosssub]

Should have no T-piece and no restrictor pill at all if you're running a boost tap (MBC). Just a straight hose from the turbo outlet to the MBC, then a straight hose from the MBC to the WG.

The MBC will have an arrow, or inlet/outlet on it showing which way around it should be. What sort of MBC is it?

[Coreybrieseman]

That's how I had it in the first place with no pill and still no boost on primary so what else can it be

[Rosssub]

Where is your boost gauge running from? Is your MBC (manual boost controller) set up on the primary WG, passengers side?

Stuffed turbo, incorrect vac hose routing or a big boost leak. Make sure all clamps are tight, especially on the pipes from turbo to TMIC.

If you have an air compressor handy you could do a boost leak test. By blocking the intake off at the AFM:

Then pump 14psi into the manifold. Any boost leaks will hiss and be obvious:

Edited September 26, 2015 by Rosssub

[Coreybrieseman]

Boost gauge is running from manifold house 11 I think and yip boost tap on passengers side

[Rosssub]

If you adjust the MBC, does it effect the secondary boost level?

[Coreybrieseman]

Umm I'm

Not sure don't think so won't boost over 10 if it does it hesitates and jolts

[Rosssub]

Rip the MBC out and just run a straight vac hose, from the primary turbo outlet to the WG. It should give 7-8psi on primary and secondary boost. Rules out any boost control problems.

As before it could be a big boost leak. Check all pipe clamps and do the air compressor test if you can.

Could also check the primary WG. Grab the WG actuator shaft with pliers and force the WG open, then let it go and you should hear it slap shut.

[Coreybrieseman]

Ok I'll try that tomorrow cheers dude

[Coreybrieseman]

Done boost leak test nothing so we're do I look at next

[Rosssub]

Did you try these?

 Rosssub said:

Rip the MBC out and just run a straight vac hose, from the primary turbo outlet to the WG. It should give 7-8psi on primary and secondary boost. Rules out any boost control problems.

Could also check the primary WG. Grab the WG actuator shaft with pliers and force the WG open, then let it go and you should hear it slap shut.

[megamac]

 Coreybrieseman said:

Umm I'm

Not sure don't think so won't boost over 10 if it does it hesitates and jolts

Are your plugs / leads / coils all good?

[Marky]

So let me get this straight

You've replaced the turbos, and now the gauge shows 0 until secondary kicks in? Then when it does it farts about like hitting boost cut?

Either

a) the primary is fcked

b) there's a massive air leak on the primary side only (only like 2 points it can leak)

c) you've ballsed up the plumbing, somehow? Maybe mixed up the main BOV line with the pressure release one by the secondary?

d) it's not actually turbo related, turns out it's only running on 2 cyls or has a huge vacuum leak and the metering is on the piss or the afm has gone or I don't know

It can't be the wastegate or boost controller, they can't make it run 0 boost

[Coreybrieseman]

Done a boost leak test found two leaks fixed then took boost controller off and done nothing so I'm stuck for ideas

[Marky]

Does the primary turbo actually spin, I am hazarding "no" by the sounds of it

[Coreybrieseman]

Yea it does it's got a wee kit there but notwhat it should have and does not show up on boost gauge

[Subirex Automotive]

what was the reason for replacing both turbos in the first place? were they seized? if yes than did you clean or remove the filters from the oil lines? if not then there is chances these turbos are rooted as well due to oil starvation. the secondary ones are easy to get to once the turbo is off but the primary one is a pain in the ass to do as it is located behind the l/h rear timing cover. check these if you havent.