I just picked up a 2006 Silverado with a 6.6 Duramaz LBZ in it. It is my first diesel. Two days after I got it the idol became inconsistent after startup and the check engine light came on.
What happens is:
-truck starts and check engine light comes on
-truck is in limp mode
-shut truck down, wait a few minutes
-start up and truck is out of limp mode
-after 3-5 engine starts the check engine light goes out and the idol smooths out
-then two days later it starts over again
I used a code reader and it is telling me code P0088, if I clear the code the idol will smooth out. Two days later the code will come back.
Anyone know what I should be looking to replace to solve this? Could this be a vacuum leak, fuel pressure rail regulator, engine control module? I did replace the fuel filter, nothing changed.