Dan,

I have no idea why it is the way it is. I suspect the leaking up-pipes are reducing efficiency, as is the badly worn compressor wheel. Perhaps with these inefficiencies PLUS the wastegate bleeding off some pressure, it comes up short.

What I can tell you is that this thing runs like a new truck now! It pulls nearly as hard as my 2005 Dodge / Cummins (325/600). I am very pleased with the performance and look forward to improving it even more (mods to come). :)

So after I get back from the Pocono 500 Oo.it's getting a new compressor wheel, repaired up-pipes and a 4" turbo back exhaust. Then I'll re-connect the wastegate and try to adjust it.

When all of this is done I'll be sure to let you in on the results, I'd hate to leave you with a cliff hanger. :-)

John

I had the same problem you have. I found a loose clamp. befor you spend any money check all of you connections from the motor back thru the motor. watch you EGT untill you get it fixed.

another .02 but I think either a line is hooked up wrong or the WG valve is bad (not sure if thats correct name)
If I remember correctly the Map sensor (been replaced) reads the boost level then sends a signal to a valve that operates the WG actuator
from his symtoms boost is going directly to the actuator
just something else to check

Could the red and green tubes to the wastegate solenoid be reversed?

Here are a couple of pics.

Just seems odd to me that if you unplug it your a happy camper. When it shouldn't open until 10-12psi by control of the map. That must mean it is opening way to early or at start up if i am understanding it right. I am rather new to PSD and learning everyday. I am just wanting to learn the solution for it for future reference.. Wonder if Robin is right, Hoses on backwards?

Dan

Ah, as far as ray is saying. WGC Valve supposed to be normally closed. Maybe it stuck open?

Dan

yes,first I would see if I could blow are through valve running and off
it could possibly be the valve or and electrical defugalty

Robin,

Thanks for the picture and diagram. From the diagram it looks like manifild pressure goes directly to the wastegate and to the valve. And the other side of the valve goes to the intake. Does anyone understand how this is supposed to work?

I'll check my plumbing later, but I think it looks like your photo.

Thanks again.
John

The MAP sends boost pressure signals to the PCM. The PCM will operate the wastegate solenoid at a pressure I am not sure of. There is always some pressure put on the actuator even during lower boost pressure keeping it, for the lack of a better word, preloaded. With the wastegate solenoid open pressure is routed via the red tube to the wastegate actuator and opens it. Excess pressure is sent via the green tube to the turbo intake hose. There is probaly more to it than this, but this is the extent of my knowledge. Hopefully someone with more ecperience will chime in.

Like Ray previosly mentioned, make sure the solenoid is normally closed.

And your more than welcome for the pics. Good Luck.

BlackJeep
John, How did the PSD preform towing on the trip to pocono 500? Did you fix this problem?

Dan,

It pulled pretty good. It was typically able to maintain 65-70 with the trailer (9000 lbs) behind it. On the long steep grades I would sometimes wind up at 60 MPH at the top. When climbing long grades at WOT it would max out at 1200 degrees and 16 lbs of boost. This was with the SuperChips in safe tow mode. I got about 10MPG with 80% highway towing and 20% secondary road towing. I only had to shift to 4th gear once, because some economy car got in front of me and slowed me down...

Overall not too bad. I may try adjusting the wastegate actuator (rather than leaving it disconnected).

Thanks for your help.
John