I have been reading and tinkering for days with no avail.

The truck is a late build 2004 6.0 and the turbo sounds/performs normal until I get into heavy acceleration at 50+MPH

Around town 0-50mph she accelerates well and the boost ranges to 0-17psi. The truck will not however go over 20psi.. ever. Say getting on the highway or trying to pass, I get into the throttle, break 17psi then "PFF PFF PFF PFF" the turbo farts and I drop to negative boost pressure.

It's like when that happens it gets stuck in Vacuum instead of boost, I loose all accelerating power and have to let completely off throttle for 10-20 seconds until the boost gauge moves back into the positive side. Once that happens I can drive it perfectly normally as long as I don't really get into the throttle.

This started last week while cruising at 80mph on a long drive. Also, I added the blue spring upgrade about a week before that. The reason I mention that is because when this issue first arose I had to continue driving another 80 miles to get home.Once home I noticed the MAF was unplugged on the intake... I may have not gotten it locked in or possibly left it off completely during the blue spring upgrade... Once plugged back in it ran better, but still having the problems stated above.

I've considered the veins getting stuck, VGT actuator/sensor, EBP sensor... I just don't know where to start. I checked the CAC tubes and they seem to be fine..

 

No leaks in the boots? Anything to read live values? 17-20 isn't much, should be 25. Clean the EGR, EBP and tube, make sure your sensors are hooked up and watch some live data.

Look for cracks/splits in boots, tubes and even the cooler.

 

I just have a OBDII bluetooth with Torque Pro App, allows me to monitor basic functions.

I shouldn't have to clean the EGR valve with it deleted, correct?

I am going to try to monitor the VGT duty cycle while driving tomorrow and clean the EBP and tube.

 

Get rid of your throttle plate. Mine was worse than yours. Not sure if it's the throttle plate actuator or the tps but it definitely caused a problem. Just ran with the actuator disconnected but my mileage seemed to drop. After I removed the plate I hooked it back up and my mileage came back. It dropped down to about 15.5mpg and its back to 17.5 -18mpg. Not sure why it dropped and don't really care but other than having a delta on oil now it running fantastic

 

Wow 250andEX, I removed the throttle plate and it is running like a champion again...

Apparently this is the only year that even has one, go figure.

Thanks!

 

your welcome. Unfortunitly we are blessed to have the one year they were in there. Most people don't realize what a problem they cause. I sure as hell didn't, but if found out the same way you did by being on here.