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Boost problems

B

BLACKanREDgtp

New member
Hey guys I have a 97 gtp an I'm having some boost problems it's only showing 4.4 lbs of boost on my gauge an my torque app an I can not figure out what is going on with it I've looked up the vacuum diagrams an it looks right an my bbv is hittin the set screw at the very bottom when reving the car an goin down the road an I have no leaks anywhere that I can find the only thing I can think to change now is the map sensor should that cause boost not to show if it's bad I'll list all my mods at the bottom thank you guys

Xp hot cam
ls7 lifters
gen v sc
gen v lim
140 # valve springs
fwi
3.4 sc pulley
speed daddy headers
zzp 1.0 pcm
ac delete
all new internals pistons rings crank bearings cam bearings oil pump double roller timing set rods newer trans
 


How many KPA's does the MAP read at full throttle?

Should be upwards of 170-180kpa if you are setup to make around 9-10psi.

Move your vacuum line source to see if you boost gauge changes.

Perhaps the BBV is causing this to, unplug it and see if you get more boost.
 
Thanks I'll try that in the morning an let ya know Scotty I removed the boost actuator completely already an it still shows the 4 lbs
 


Well i switch all the vacuum lines today just in case one was cracked an i by passed the bbv an its still only running at 4lbs i honestly dont know what else to try im getting frustrated with it
 
Hey ive been super busy at work but i did spray the top of the bbv wit carb cleaner an all around everything they could leak an i never heard the rpms jump up but i got a video finally ill post ot on youtube when i get home an ill post the link an you guys can see if you see something i may be over looking thank you guys for all your help
 


Lol yea i just cant figure out whats causing it i sprayed carb cleaner all over everything an didnt find any leaks any where an i changed all the vacuum lines incase they had any little cracks in them an double checked the vacuum diagram to see if it was gooked up wrong an ot all seemed good i drovenit yesturday an at wot its only showing 4.6lbs of boost i bypassed the bbv completely an it showed around the same maybe lkke .2 or .3 more i know the cam an the headets will take away a little boost but i figured it would be more than 4.5lbs of boost i believe a stock gtp has 6 or 7lbs idk i could be wrong im juat getting real frustrated with it the only other thing i know todo is replace the map sensor an see if maybe it will help other than that im running out of ideas
 
stock is like 7-8 psi, add headers your down to 5 on a stock pulley.

how are you reading your boost? your map might be bad too if your reading it off the obd2.
 


Ok so you bypassed the boost control solenoid. The solenoid the ECM uses to dump boost for traction control and reverse. So does the boost bypass valve open and close? Is one end connected to the top of the supercharger and the other open to air? If you manually keep the valve forced closed how much boost builds?
 
Yea im reading it off the torque pro app thru the obd2 i have a regular boost gauge but i dont have it hooked up yet its a gen v running a 3.3 pulley brettstoner therea a video link i put up thay shows the bbv moving an the vacuum lines take a look an see if you may see something ive over looked
 
that vid link dont work, its like yt home page.

might want to try another map sensor then.

is your sc screaming? or is it lacking the whine?
 
Ok sorry ill try to post it again it whines but i dont remeber if its as loud as it ahould be ill drive it tomorrow an let you know i really appreciate all you guys help
 
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