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4psi!! help!!

iluvbst

iluvbst

New member
ok, i got my boost gauge today. hooked it up, went out for a drive and...4 psi!! uve got to be kidding me! what could it be? isnt the stock psi like 8. if i had a boost leak that big...wouldnt i hear it as a vac leak? idk someone enlighten me..this is my first supercharged car and first gtp.
 


What does the vac side say at idle sould be around -20
If its lower you may have a vac leak

could also be a bbv issue
 
stock pulley...everything is stock, except u bend and cat delete....thats the other thing, stupid boost gauge doesnt have vac on it!..cheap **** lol, but looked and listened all arond the motor, dont really hear anything, sprayed starting fluid around to see if i hear it, but nothing...now i think the coupler is going bad in the sc, i hear it knock sometimes..but still dont think that should cause that..should it? and another thing is the bbv, im guessing thats the actuator with 2 hoses on it on the sc...well i unpluged both hoses and still 4psi..but i can hear the sc more, sounds more whiny..i know thats alot but, thats whats going on...
 
could be 3 things, could just be bad calibrated, line going to it maybe pinched, or you got an issue with the car and its really only making 4psi.

hows your belt look? do you have black marks above the pulleys on your underside of your hood?
 


havent really looked..but i know the belt could use replacing, but would that cause such a boost lost?
 
I have headers but I sit at 5 PSI till the top of the gear where I see 7 PSI.

Suggests the valvetrain is having some issues up there....

Same mods at Gafford.
 


matt5112 said:
I have headers but I sit at 5 PSI till the top of the gear where I see 7 PSI.

Suggests the valvetrain is having some issues up there....

Same mods at Gafford.
Click to expand...

wait matt you think i have problems? my system is rich right now havent got the retune yet
 
Could b the belt? some 1 i kno had that prob! he would only see 7-8lb on a 3.0 pulley, new belt 11lb ;)
 
well just bought a vac gauge today, ill test it, if i dont get anything, ill try a new belt...oh yeah and the vac line is hooked up between the manifold and the fpr...looks like a good place to me. lmk if its not
 
ok well i got like 19.5 in of vac..so...guess the belt is next...just dont understand how a belt could cause that problem, what does it slip or something?
 
is everyone in this thread serious? how has no one mentioned that when the BBV solenoid is active that the car is limited to 4-5 pounds of boost? this 100% sounds like your BBV is acting up.
 


Bio248 said:
is everyone in this thread serious? how has no one mentioned that when the BBV solenoid is active that the car is limited to 4-5 pounds of boost? this 100% sounds like your BBV is acting up.
Click to expand...

I was going to, but he pulled both vac lines off the actuator, effectively shutting the BBV completely, and didn't notice a difference.
 
Bio248 said:
is everyone in this thread serious? how has no one mentioned that when the BBV solenoid is active that the car is limited to 4-5 pounds of boost? this 100% sounds like your BBV is acting up.
Click to expand...

ive been waiting for you to come to my thread...seems like you know alot about these beast...so if the bbv is bad, why when i unplug both vac hoses, i still get 4-5 psi..more like 4. but the only difference as i said before is the sc sounds be whiny,like i can hear it more...i also just took the belt off, have a bad coupler, would that cause this?
 
a coupler wouldnt cause low boost, it has no way of doing that. if you did test the BBV and its still doing it then im not sure.

you said you just got the car? whats the potential that someone hogged the crap out of the blower case and youre just making low boost because of it? are there any mods on the car at all that you can tell?
 
no, car is bone stock...guy didnt even know how to put on an air filter..lol all i did was the u bend/cat delete. i figured the coupler wont cause that, what about the belt? but if anything...i have another sc, with new coupler and 3.5 pulley..dont think i can run that yet can i?
 
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