can't boost over 5psi

[93AWDTalon1]

The car does great until it hits 4-5psi and then acts like it's cutting out or hitting some kind of limiter. but I don't have a fuel cut and I'm no where near the rev limit. the o2 sensor reads .92-.94 under boost. it has week old ngk's in it. everything looks good on the pocket logger but it acts like it's hitting some kind of limiter over 4-5psi. anyone got any ideas?

 

[justin0469]

do a boost leak test and you problem will most likely be very evident within minutes.

 

[93AWDTalon1]

say its not a boost leak what else could cause that?

 

[justin0469]

i dont see it say no boost leak. fuel cut is not the same thing. not even close. and the only way you know its not boost leak is to do a boost leak test

 

[93AWDTalon1]

no boost leak, to add to this I can't go over 5k reving in neutral

 

[justin0469]

how do you know theres no leak?

 

[93AWDTalon1]

because I tested it at my friends house with his boost leak tester

 

[SBstar]

I'm assuming you have a mbc, do you have it hooked up correctly? http://dsmtuners.com/forums/showthread.php?t=105573

Is this a problem you've had for a while or something that just came up? Have you done any recent modifications or removals on the car?

 

[93AWDTalon1]

no new parts have been put on, the car use to be able to hit 20psi with the mbc set like it is what ever happened just happened

 

[SBstar]

Hmm tough one. You've done the boost leak testing which was my first guess.
Could be your turbo taking a poop on you i suppose, the wastegate might not be working properly. After reading around some I found out that alot of people have a bad wastegate, it's being blown open to soon.
OR
Defective turbo or failure caused by oil feed/return/pressure issues.
I'm assuming you're referring to the car you have in your profile so I would check on the wastegate (is it internal or external).
Also check to make sure all your plug wires are connected down properly.