I am wondering, I am having an issue with my boost just had the clutch and and tranny replaced, it was having this issue before this, i dont know what the owner before me did to it mods wise, other than a manual boost controller any advice. What the problem is the turbo spools but i only get 5-8 pounds of boost and thats with the boost controller the hole way up

 

You can start by checking vacuum lines from And to your boost controller.

 

yeah with a clutch/tranny swap a number of lines could have been pinched or have a pin-hole in them, start with things that are necessary to build boost, don't think it's caused by the tranny or clutch...

 

Hmmm..... 5-8 PSI seems pretty lame to me.

 

I am having the same problem but mine hits 15psi and holds there. Doesn't matter if I crank up the boost controller higher. Almost seems like it is set at 15psi and stops abruptly.

I also replaced the clutch in the car, so I will tear back into it to make sure no lines are pinched somewhere.

If you are running a manual boost controller, can the ecu control the boost anymore? I have another theory on why it is down, it was down about 4 psi before I did the trans swap and thought that the ecu might reduce the boost due to knock, hence my question.

 

I would guess something isn't right with your mbc. That is roughly wastegate pressure. I think the IX is 18psi. Your car tuned? Is the mbc installed correctly?

From what I hear (this would apply to both of you guys) is if you ever have a coupler blow off or piping removed, you need to do a boost leak test. Leaks in your couplers, DV/Bov or even your turbo will cause all sorts of havoc on a car.

 

I am in the middle of doing a boost leak check now. I hear a lot of air, but really couldn't pinpoint the location. I finally wiggled the throttle shaft and I can hear the air cutting in and out. So I will be replacing that and hopefully that will take care of my problems!

Is air supposed to come out of the little hole on the MBC on the back side?

 

hey i had a similar problem recently my car was not going pass 19psi even though the mbc was all the way up.i found out though that the boost gauge vacuum line was pinched so the gauge was reading wrong.If the car feels strong and the boost doesnt look right check that out.Also it will throw out your vacuum pressure at idle.

 

Thanks for the info! I had that going through the back of my mind and haven't checked it yet.

UPDATE: The hose going to the boost gauge had a huge hole in it! When the clutch was being replaced the engine was leaning way down and pulled on the hose and cut a hole in it.

The throttle body bushing also was cut and leaking air pretty bad. I haven't taken it down the road yet but, I am thinking that it should be good to go!

Thanks for all the comments and sorry about hijacking the thread, but I was having the exact same symptoms as the OP.

 

nise just as i thought good to hear you find it.