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Topic: Boost issues (Read 5403 times) previous topic - next topic

Boost issues

so how do i check for a bad turbo? I have no boost at all till i floor it and when i do that i get 2 lbs of boost but when i let off back to 3/4 throttle it goes to 0.
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com


Boost issues

Reply #2
Quote from: Cougar8775;312272
so how do i check for a bad turbo? I have no boost at all till i floor it and when i do that i get 2 lbs of boost but when i let off back to 3/4 throttle it goes to 0.


Wait...are you trying to build boost while just sitting in the car and revving it? Or is this while you're actually driving it?

You only get boost under load...free-revving will not get you boost.

If this is what you're doing, no boost is normal.



If this is happening while driving, then...

You should be checking for boost leaks before you check for a "bad" turbo.

You should also check to see if the wastegate is working properly.  The WG flapper could not be closing all the way.

Both of these could cause low boost situations.  A "bad" turbo would let you know by blowing clouds of smoke, or making nasty noises.  They're not complicated devices, and don't just go "bad" and stop making boost.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Boost issues

Reply #3
ok so it could be that the wastegate could just be stuck open. Where is the wastegate located?
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #4
Usually on the  turbo...
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

Boost issues

Reply #5
First...Check EVERY hose and connector between the turbo and the throttle body.
Make sure there are no split connectors and they are all tight.

If this is good, then look into the wastegate.


The wastegate is located on the exhaust side of the turbo.  On the IHI turbo it is part of the turbo itself, instead of the outlet elbow.  There is a rod underneath the turbo that connects the wastegate actuator to the wastegate flapper.  The wastegate actuator is the diaphram-looking thing mounted on the compressor-side (front) of the turbo.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon

Boost issues

Reply #6
cool thanks going to check it now.
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #7
ok i found that rod now is there any way to check to see if its working? and can you move it without the engine running? cuz if you can i couldn't get it to move at all.
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #8
you shouldnt be able to move it without a considerable amount of force.  there for you know that your wastegate is closed ;)

Boost issues

Reply #9
so how can i tell if its good? since i tightened the couplers i got 4 lbs of boost when i floor it.  And how can i tell if its bad?
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com


Boost issues

Reply #11
yeah but one is kinda odd. it runs from the turbo then hooks to a "t" then it runs into the other "t" on the firewall, then runs to the  drives fender well then from there im not sure. and from the turbo to the "t" there are check valves so vaccume can only go one way. and the line runs to the compressor side of the turbo.
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #12
do you have a diagram on how the vac lines run to and from the turbo so i can check them and make sure there right?
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #13
got the diagram found my issue. Someone put the main vac line to the wastegate so it opens when vac is put to it so no boost. I will fix it in the am and report back.
2001 Buick Regal LS (DD):hick:

Got that fox rash again!

-Resident smartass! :ies:

- Don't listen to the naysayers. For every person who actually helps with your project there will be 10 who will discourage you all the while thinking that they are helping. 99% of all people have good intentions. That doesn't make them right.- XR7 Dave - SCCOA.Com

Boost issues

Reply #14
you have to carfully  use compressed air into the hose that runs to it... if you force it too much you will pop the diaphram
1985 TC (yet another one) Fully loaded
has 225k mile  still with the factory head gasket






84  Turbo ranger  Daily driver  ($800.00 Ebay deal)
          volvo FMIC and more getto rigging than the law should allow