issue with low power and "boost surge??"

[vinnio]

I just started noticing a low power issue in my car. Basically, I'm not getting the power it should get. I haven't dynoed it or anything, it just doesn't pull as hard as it should on the street. It seems like there is little low end torque. As soon as the turbo spools up, it pulls, but not as much as it should. Another thing that has been happening is when my turbo fully spools up, it surges back and forth between 12 and 15 psi (sometimes even 10 to 15) I have my boost controller set to 15 psi so I don't know...

I did a compression check and it came up 125 to 130 across the board.

The check engine light came on with several codes.
A p0400 (evap???)
A p1400 (mdp or map sensor, but i cleared that and the code hasn't returned like the others)
A knock sensor code (don't remember which)
And an egr code (don't remember which) but that turned out to be my egr vacuum line was just unplugged... It solved my poor fuel economy but not much else.

It does take a while for my turbo to spool up, but I assume that's because of the larger (16g) turbo I have.

I'm close to being at a loss. I am mechanically inclined, so I can usually figure things out. I have worked on many cars, but this is my first turbo car, so this is all new territory. The check engine light just came on again last night, so I will read the (new, or old) codes and get back to you.

TIA
Vinnie

 

[spoonman]

Try a boost leak test. If there are only tiny boost leaks that you fix them, and the problem continues then your waste gate is faulty. The pressure line could be leaking or the actuator is bent or stuck.

 

[vinnio]

Thanks. I will check for boost leak. I guess I have to make my own tester tho... Also, I re-did the compression check with a better gauge and its reading 170's on all four. Woofta. After I posted the original thread I found out that the min is 133psi, so I was worried for a while.
Thanks again,
Vinnie

(I will try to rig up a boost leak tester tonight)

 

[Street_Killer]

Is there a line hooked into your bov? Mine fell off once and did that.

 

[vinnio]

Okay. Here is what happened tonight. I had another CEL that came up. It was a p1400 (map sensor) I have a new one on order so it should be here tomorrow. I find this good news because I have always suspected the map sensor. I didn't get the time to rig up a boost leak tester tonight, but I will run to the hardware store tomorrow. I did check the line to the bov and that was connected with no leaks. I will get back to you all tomorrow with more results (hopefully results)
Thanks again,
Vinnie

 

[vinnio]

Not that it matters too much because this thread was from a while ago... But it turned out to be a faulty waste gate actuator. Very easy fix. Took care of it right away, at least until something else happens... .

 

[shuiyuan]

i hit my stock intercooler and made a hole on it, after that my car has simular problems as your and also fuel cuts.