please help, low boost

[turbomoe]

my car is only showing that i can only get 8psi, it is a 95 bone stock gsx, it always boosted at15, no i changed the bov and still same problem,

i even unhooked the wasted gate vacum and only got 9 psi, what can it be please help

 

[juanpac0]

Now, this isn't going to be a 100% answer, but chances are you have a boost leak, as do 99% of the people who make posts like this do. Did you do anything before you stopped being able to build the boost?

 

[boostforfun]

Also, pull intake hose to turbo and check shaft play.

I agree with above poster that it could be a boost leak, as tubos very rarely just go out without some fanfare (smoke, oil blowby, and the like)

If there is a large boost leak, dont keep trying to boost it to the sky, as you are overspinning your turbo. The turbo it tring to create more boost, but it cant. So, the turbo could be making 20psi, but the engine is only seeing 8. I ruined a turbo on one of my dodges this way (hole in the intercooler)

 

[talondave]

Did you lose power in your car? If not maybe your line to the boost gauge has a leek!

 

[95TSInsane]

Hey guys! I did some looking into other forums but could not come up with an answer.
I just installed a new mbc and vac hoses yesterday but im having some boost issues. I am only able to run 5 lbs of boost. I cant go past in not matter how many clicks i turn it up to. Any thoughts or ideas. thanks.
P.S. i did run all my new vac lines correctly when putting the new mbc in.

 

[Boost92awd]

Have you checked for boost leaks?

 

[boostforfun]

are you ABSOLUTELY SURE you ran your lines right?

If it was boosting before you put it in, and not after, then you should go back to the only thing that changed.

did you put in a ball and spring MBC? If you did, make sure your lines are right on inlet and outlet.

Somehow the actuator is getting straight boost signal and is opening at spring pressure.

 

[95TSInsane]

i did a boost leak test yesterday and everything seemed to check out ok but i will check my lines again to make sure everything is good.

 

[boostforfun]

Have you checked for boost leaks?

I was assuming he would be talking about poor performance if there was a large enough boost leak to keep it at only 5psi.

I still vote for lines not on right... I know i did it wrong the first time I put one on

 

[boostforfun]

Is there a "T" into your line after the boost controller? Just make sure the line between the wastegate and the MBC is uncut and no "t"s

 

[95TSInsane]

Nope the only t is before the controller

 

[dsmfa9nutter]

Make sure your wastegate is staying closed (like that the control arm is on and secured with the little clip). I had the same problem and it turned out to be my wastegate actuator arm slipped off the wastegate flapper. At wot I was making 5lbs of boost with the flapper wide open.

 

[shortyskater]

+1 on checking the vac lines again. The controller should look like this:
|- the connection in the middle should go to the J-pipe and the one from the bottom to the wastegate.
Also check to see if the wastegate arm is still connected. If not it will just flap.

 

[95TSInsane]

Ok i got her figured out. Did a leak test one more time. Found one of my hoses was a little to big for the controller. replaced it and works primo now. thanks guys for the insight.

 

[shortyskater]

Probably a small leak somewhere. Check the acutator arm and make sure its still connected.

 

[ilco187]

i dont know about 2g's but on 1g a faulty pcv valve can cause boost leak into the crank case. all that air is gonna do is recirc, through the intake, i have a 92 auto awd and it used to boost 14 but when the pcv valve faulted it was only 7lbs.

 

[No_Skillz]

Boost leak test. And if you can only get 9psi with the wastegate vac unhooked, it's a massive leak.

 

[boostforfun]

at least its fixed. good find.

 

[turbomoe]

My Car Is Wont Go Past Nine, I Changed The Pcv, And Boot Leak Tested, No Shaft Play On The Turbo, Can A Bad Mass Do That? It Just Happend Over Night? I Cant Get It To Run Right, I Added A Hks Bov And Still The Same, I Changed The Boost Gauge Line And Still 8 Psi

 

[shortyskater]

Do you have some way to control boost? Try messing with that if you do. I don't believe a bad MAS would do that but I could be wrong. Check, double check, and re-check for leaks. Sometimes the smallest pin hole leak can throw things out of wack.

 

[boostforfun]

moe,

you said you removed the wastegate line, and it still opened at 9psi?

Do me a favor and physically try to pull on you wategate actuator arm, you should not be able to move it much. If you can, something got damaged inside and it is unable to hold the wastegate shut. Unlikely, yes... possible, maybe....

Actuators do go bad from time to time. I had one crap out on my 95 tsi.

 

[turbomoe]

waste good is good, nice and stiff, okay well i did a boost leak test again, and i think i found a small leak and fixed it, this is what i get know

1gear 5-7 psi
2gear 7-9 psi
3 and up 8-10

 

[ilco187]

does the car "feel" slower or just "showing" low boost pressure, the stock gauge could be miscalculating.

 

[boostforfun]

does the car "feel" slower or just "showing" low boost pressure, the stock gauge could be miscalculating.

I was under the impression he had an aftermarket gauge.

 

[turbomoe]

it is a aftermarket gauge, no its slow as balls, 15psi is were i wanna be,