evolv

iTrader: (11)

Hi guys, just looking for some input on this, sorry for the long read.

Earlier this week, my boost just started toping off at 11psi. So I did a couple 3rd and 4th gear pulls and sure enough it flatlines at 11psi. My first thought was a boost leak or hose got loose somewhere. So I tightened all my clamps and took it for another run, no changes. So I checked all the hoses on my blitz sbc and egr valve, everything looked good.

So I decided to put together a tester and run some air through it, sure enough at 11psi I start hearing the throttle body hissing. If I play with the throttle cable or push the spring a little, the noise changes.

After much searching, I found some topics on the throttle body seals that can go bad, and seemed to explain my issues.

https://www.evolutionm.net/forums/sh...=throttle+body

Now my question, is it possible that bad TB seals could cause this much boost loss? I mean, I flatline a 11psi (11.4 actually) but most of what I've read on this issue people see a few psi loss and its gradual.

Any other ideas would be helpful, I did order some new seals today but they wont get here for a week so it gives me time to try other ideas.

Thanks!

SLOWRREX

iTrader: (1)

Not sure if this helps,but,when i bought my car.There was a mbc in it..It was hooked up wrong,and i was hitting btween 11-12 lbs of boost.I was told that i was running off the WG..But,if you checked for leaks,this doesnt sound like the same problem..Good luck..Hope you get your probs worked out..Justin

sparky

iTrader: (1)

So, what was your previous boost level, before you started flatlining at 11#?

evolv

iTrader: (11)

20-22 on 93 octane (daily driving)

gsrboi80

iTrader: (38)

You wouldnt lose that much boost from the TB seals leaking

GIsnickers

iTrader: (3)

check your pills on the boost control solenoid, they might not be in the correct spot or reversed. this will cause the boost to top out around 11psi

the tb seals might be the first thing your boost is leaking at so you might not hear a bigger leak down the path

i would fix that first

when i had that problem i just ordered the buschur throttle body so i wouldnt have to worry about it again


what kind of blow off valve are you running, that may be opening up prematurely as well

tons of things to check with this type of problem

evolv

iTrader: (11)

Well it ended up being the controller so all is good now. I am going to put the seals in anyways to prevent issues down the line, thanks all