boost problem

[1992LaserRSAWD]

I finally got to do some wot pulls last night Here is my problem I have the mbc turned all the way down but it will still hit 20 psi. Also in 3rd gear when it hits 20 psi it feels like I hit fuel cut and as soon as it does that it pegs the boost gauge. My mods are in my profile. Anybody know what could be the problem?

 

[urcnjoe]

I finally got to do some wot pulls last night Here is my problem I have the mbc turned all the way down but it will still hit 20 psi. Also in 3rd gear when it hits 20 psi it feels like I hit fuel cut and as soon as it does that it pegs the boost gauge. My mods are in my profile. Anybody know what could be the problem?

The first thing I would check is to see if you have the MBC hooked up properly. Make sure you have the proper nipple connected to the pressure side, and the other to the waste gate. Do that first then check back in.

 

[oldman]

Which mbc and how's it hooked up?

 

[peregrine]

I finally got to do some wot pulls last night Here is my problem I have the mbc turned all the way down but it will still hit 20 psi. Also in 3rd gear when it hits 20 psi it feels like I hit fuel cut and as soon as it does that it pegs the boost gauge. My mods are in my profile. Anybody know what could be the problem?

first i would pull your MBC and just run a line from your turbo to your wastegate to eliminate the possibility of a stuck wastegate. second it sounds like fuel cut to me, get a chip (didnt look at your mods). let us know.

 

[1992LaserRSAWD]

just a generic boost controler I got off of ebay.here is a picture of how I hooked it up.

 

[1992LaserRSAWD]

won't be able to run any test until my day off on wednesday.

 

[oldman]

first i would pull your MBC and just run a line from your turbo to your wastegate to eliminate the possibility of a stuck wastegate.

Yes, do this and post back.

 

[1992LaserRSAWD]

first i would pull your MBC and just run a line from your turbo to your wastegate to eliminate the possibility of a stuck wastegate.

did this and car will only boost to 10 psi then.

 

[oldman]

did this and car will only boost to 10 psi then.

Then it's either a bad mbc, hooked incorrectly or adjusted in the wrong direction.

 

[Reese92tsi]

Make sure you don't have any holes or slight cuts in your vacuum lines

 

[silvah_gsx]

Did you check to see that the hoses are not too long? I ran into this same problem, I'd hit 2 BAR (almost 30 psi, on a t-25 ) with the MBC mounted, well, too far from the Turbo. I cut the hoses to be as short as possible and mounted the MBC above the radiator, and now it reaches 15 psi very quickly, and stays there.

 

[92awddsm]

I had that mbc once upon a time and it was a pos. You probably need to disassemble it and cut a coil off of the spring. Better yet, go ahead and buy a good mbc. Mine would full boost with the adjusment backed all the way out. Once I modded, it wouldnt go below 16psi and when I started to turn it up, it woudnt go over 21psi. I installed a halman shortly after and all my boost problems went away. I could adjust from 12psi to 25psi with no problems. I still have it and on my 60-1, I can turn it all the way to 30 psi and it still works flawlessly. I have yet to go over 30psi so I cant tell you how it will work beyond that.