Only 10 Psi of Boost HELP ME PLEASE!!!!

[Underboost]

Hi everyone!

This is weird I can only get 10psi of boost. I have checked the hoses, turbo blades, puck on the down pipe, plenum gasket, disconnected the waste gate still 10psi, checked boost gauge with another boost gauge, put new headers on, and checked all vacuum lines.

I am about to pull my hair out.

PLEASE HELP ME!!!!!!!!!!!!!!!!!!!!!!!!!!! Thanks Guys

 

[Blazer406]

You might try and unhook the wastegate actuator... and put a stiff spring holding it closed.... drive it.... ease into it and see if she goes above 10... be carefull.... cause if you nail it.... it might go to 30......

 

[Underboost]

You might try and unhook the wastegate actuator... and put a stiff spring holding it closed.... drive it.... ease into it and see if she goes above 10... be carefull.... cause if you nail it.... it might go to 30......

Iv'e done that and nothing. But Thank You

 

[daverr]

howabout after the turbo.plugged cat? muffler???

 

[Underboost]

howabout after the turbo.plugged cat? muffler???

Unhooked straight pipe from the down pipe and ran it. Still 10psi

 

[Underboost]

I'm sure it's something dumb!

 

[Blazer406]

If your exhaust is free... and you have no restriction on the intake..... You need to look elsewhere.... does the turbo spin freely? Have you CLOSELY inspected the compressor fins? turbine fins? I know you said you checked alot of stuff.... intercooler got a squirrel's nest in it?

Do you have a scantool?

 

[Blazer406]

You said you checked hoses..... hole/split in the intercooler hoses could cause that...... do you think you might have a hole in the intercooler itself?

 

[Underboost]

If your exhaust is free... and you have no restriction on the intake..... You need to look elsewhere.... does the turbo spin freely? Have you CLOSELY inspected the compressor fins? turbine fins? I know you said you checked alot of stuff.... intercooler got a squirrel's nest in it?

Do you have a scantool?

No Scantool :frown:

Yes turbo is perfect! Squirrel's nest?

 

[Underboost]

You said you checked hoses..... hole/split in the intercooler hoses could cause that...... do you think you might have a hole in the intercooler itself?

I'm going to take each hose off tomorrow morning. I had a friend power brake the car and I herd nothing and saw nothing. I have also felt under all of them and nothing.

If the hoses are good then I will need to pressurise the intercooler like they do when they check your radiator leaks.

 

[TURBOV6]

I'm going to take each hose off tomorrow morning. I had a friend power brake the car and I herd nothing and saw nothing. I have also felt under all of them and nothing.

If the hoses are good then I will need to pressurise the intercooler like they do when they check your radiator leaks.

Just becareful you don't powebrake it too long and let the engine run before you shut down. I learned it the hard way and blew my pump on the tranny

 

[terryjh6]

i had the same problum with mine (TERRYjh6) cleaned and streched my spring(be very careful it only takes a LITTLE bit) on my rjc boost control and now i'm good.. and yes i DID have some type of nest in my air cleaner when i first got my car . it would build about 8-12# of boost and a lot of black smoke also first time out i hit 30# hope everything is ok

 

[Underboost]

Just becareful you don't powebrake it too long and let the engine run before you shut down. I learned it the hard way and blew my pump on the tranny

I blew the drivers side rear brake cylinder instead.

 

[TURBOV6]

I blew the drivers side rear brake cylinder instead.

Lucky, I had to rebuild the tranny

 

[turbolou]

Reply

No Scantool :frown:

Yes turbo is perfect! Squirrel's nest?

Maybe it's two squirrels! The one behind the wheel & the other his mechanic LOL

 

[wiked87gn]

Maybe it's two squirrels! The one behind the wheel & the other his mechanic LOL

So i guess your calling yourself a squirrel, because if im right You are his mechanic lol, Just kidding Lou, i know you been having a hard time with that car but eventually you will fix it cuz ur a stubborn SOB who always finds the problems and fixes it..

wiked

 

[turbolou]

Reply

So i guess your calling yourself a squirrel, because if im right You are his mechanic lol, Just kidding Lou, i know you been having a hard time with that car but eventually you will fix it cuz ur a stubborn SOB who always finds the problems and fixes it..

wiked

Yes it's fixed !

 

[Blazer406]

Are you not gonna tell us what it was?

 

[turbolou]

Reply

Are you not gonna tell us what it was?

As with any problem like this once you find it you curse your stupidity for not finding it sooner. It's very easy to get thrown of course & in the wrong direction. To make it brief the car came in with a low boost complaint along with other related issues. Broken headers,piece of exhaust turbine blade missing,tuneing problems etc.All which were eliminated as the search went on. Still couldn't get over 10# boost. The kicker was the car actually ran well & was getting knock counts even using alcohol. Suspected a faulty gauge & hooked another to verify still same problem.What I did notice was fuel pressure readings that were high under wot indicating high boost pressure getting to the regulator. Then hooked gauge splice into regulator hose & buried the gauge past 25# then traced the problem to a split hose underneath at the t/body vacuum block.It was sealing itself at idle & opening up under boost which was the line feeding the gauge, There again this car has had a history of goofy problems & has been an ungoing process of elimination.

 

[Underboost]

As with any problem like this once you find it you curse your stupidity for not finding it sooner. It's very easy to get thrown of course & in the wrong direction. To make it brief the car came in with a low boost complaint along with other related issues. Broken headers,piece of exhaust turbine blade missing,tuneing problems etc.All which were eliminated as the search went on. Still couldn't get over 10# boost. The kicker was the car actually ran well & was getting knock counts even using alcohol. Suspected a faulty gauge & hooked another to verify still same problem.What I did notice was fuel pressure readings that were high under wot indicating high boost pressure getting to the regulator. Then hooked gauge splice into regulator hose & buried the gauge past 25# then traced the problem to a split hose underneath at the t/body vacuum block.It was sealing itself at idle & opening up under boost which was the line feeding the gauge, There again this car has had a history of goofy problems & has been an ungoing process of elimination.

I Thank You again Lou!

The car runs like a raped date now. :biggrin:
I'm very,very impressed. Thanks Lou, Brent
P.S Now I can out run that one big SHEEP! LOL