My CRD has been throwing overboost codes for a week now. If I rev it over about 2000rpm it will throw a P0234 and go into limp mode. So I bypassed the boost solenoid, etc, with no luck. Initially it seemed like the actuator was moving normally, but now it barely moves when I remove and replace the vacuum line. So I figured, OK, I'll work the actuator a bit and see if I can free it up (since I can't give it a hard-run to try to burn it out). I worked my hand back in there to grab the bottom of the actuator lever arm and pulled for all I was worth and couldn't hardly budge the arm. So then I grabbed the Mityvac and applied vacuum to the actuator. It doesn't move at all until about 15PSI, and then only 1/4" to 5/16" up to about 20PSI. I did this a bunch of times and it didn't make any difference. So Finally, I reach back to grab the actuator arm again and as my hand runs past the lock nut on the arm, it spins freely! I can run it all the way to the top and back with no resistance. So now I have no idea how much the actuator arm has moved during all of this. I pulled the front (intake) half of the turbo off in one piece to work on it on the bench. The vanes in the exhaust half move freely and the actuator in the intake half seems like it can move fine...it is just the downward pressure from the actuator preventing it from moving. I have not unbolted the actuator puck from the turbo body to try to move JUST the actuator arm. I don't know what the vacuum pressure is supposed to be for a CRD, but it doesn't seem like it is anywhere near 20PSI...so at what pressure should I expect to see the ideal 1/2" actuator movement?
Should I be able to move the actuator by hand with the vacuum lines removed and the puck connected?
At what pressure should the actuator be fully engaged?
How do I determine where the adjuster needs to be set on this thing?!?!
HAAAALP!!!