I can Only Boost 9 Lbs. on Every Turbo I Buy!

[scottr126]

I have a 1990 Talon TSI AWD, when I first got it with the 14B I put a Starion FMIC and a Manual boost controller on it And for some reason with the Boost Controller I couldnt boost any more than 9 Lbs. It wasnt the boost controller that was the problem I tried my buddys TurboXS one out and it was the same thing 9 lbs MAX. So I just recently got a 16G and put it on, at first I boosted like 14-15 lbs no problem but the next day I went to go try it out and it was the same damm thing!! It only boosted to 9 Lbs max. It really sucks my car cant be fast!!! Any ideas what can be wrong?? Oh ya also, i checked for boost leaks with a tester i made to pressurize the system and I didnt find any.

 

[fertez_turbo]

Are you sure the boost gauge is hooked up correctly?

If so, maybe your wastegate is stuck open.....

 

[scottr126]

Yah the boost gauge is correct,when I first installed the 16g it was reading about 15 lbs and the wastegate is firmly closed i just checked the Actuator.

 

[Coldandafraid]

take the hose off of the wastegate and see if you go over 9 psi... but be careful. Maybe a bad boost gauge connection or something...

 

[fertez_turbo]

Or maybe youre leaking boost somewhere...
Check all your intercooler piping and the BOV to make sure there are no leaks. Maybe try messing with the boost controller as well, turn it up and see if it does anything....
-dale

 

[4geze63]

vacuume leaks possibly, mine was boosting to 8-9 psi, got the leaks fixed and now upto 12.5psi on the 14b/w freemods

 

[TalonRacer18]

I say boost leak, or theres a crack or something with that starion, plus i hear pressure drop is a biotch with those.

 

[scottr126]

Well Like i said I already did a boost leak test and Fixed a leak I found and now it seems to be air tight but I still am getting only 9 lbs with the wastegate disconnected. Is it possible that the BOV can be bad and be leaking at that low of a psi??? It is the original on with 98k on it. I think im gonna try crushing it a little and see if that helps.

 

[Willjs7]

Yes a bad BOV can do this.

 

[turboholic]

-If you have a mityvac, test the BOV to see it open what psi, crushing the BOV will hold more boost.

 

[scottr126]

Mityvac? What is it? A vacuum?

 

[turboholic]

http://www.mityvac.com/

 

[scottr126]

Alright heres whats goin on, I just did a boost leak test and found a few small leaks, I fixed them all and now when I put alot of pressure into the system the only place I hear air coming out is the BOV dump tube. So I took it for a cruise and sure enough NO difference, only sometimes tapping 10 lbs, then I stopped, disconnected the wastegate and sure enough No difference once again, 9-10 lbs MAX. So really the only thing it can be is the BOV. So I want to try and block it off and go for a quick drive, I know compressor surge isnt cool but I just want to see if when its blocked I can go higher than 9 lbs. Would it be ok to block it off for like a 1/4 mile drive?

 

[TalonRacer18]

you could seriously damage your turbo doing that. Just find somebody around you or someone you know that has a known working bov and use theirs. What bov do you have?

 

[scottr126]

i have a stock bov currently.

 

[turboholic]

Originally posted by scottr126
i have a stock bov currently.

-Take off the BOV and clean the seal with some carb cleaner or something, you can see if the gate is clean or not once it's off the pipe.
-To crush the BOV, set the BOV on a bench vice sideway, put/tape a penny on the lid of the BOV, close the vice, you want to concave the lid of the BOV so it put more tension on the spring inside, I use a pump while crushing to check mine so it open at 18psi, there's also a thread at the tech section on how to modify the BOV.

 

[scottr126]

well i dont get it I crushed the bov and now its hard as hell to open but still does, i have NO boost leaks i did a couple tests to make sure and I disconnected the wastegate line and i still max out at 9 LBS!!!! on a big16g! i dunno, anyone got any other ideas what could be wrong?

 

[scottr126]

Ive been lookin through the forums alot to get an answer to this. And I have seen alot of people talk about possible timing and knock issues that can prevent the car from reaching or using full boost. Could this possibly be a problem with my setup? I notice that every time a start it up there is this sort of grinding sound from the motor bay for like a second every time i start it but it never happends any other time, what could that be?

 

[Lordpaxin]

The ecu can cut boost if you are knocking.

also, check your base timing.

also, if you are still on stock exhaust, your Cat might be plugged up.
and the intercooler could be plugged up too.

2 problems i have had.

 

[scottr126]

How does the ecu cut boost if I have a MBC? Also how would I stop knock , I always run 93 octane and also where is the knock sensor? My cat cant be plugged because I dont have one and the intercooler cant be because i just re-did all my intercooler piping and checked it out.

 

[Lordpaxin]

ok.

um, the knock sensor is located on the back of the engine under the intake manifold, the connector is mounted on the back of the manifold around the coil pack.

i have read the ecu will screw with timing, if knock is noticed to a certain level. is it possible that a drastic timing adjsutment could slow the turbo to only produce 9 psi? in my mind i would think so.

the thing to do is get a datalogger or someting and watch the knock as you launch, see if its knocking, or it might show several other sensor readings that might be helpful.

 

[scottr126]

Well guys I fixed the problem, I dont really know how though. With Christmas money I bought a 3" Turbo-back exhaust, TMO chipped ECU and a Logger. Now I boost as much as I want, I currently have it set at like 14 lbs though. Im guessing the ECU was messing with it or something.