Originally Posted by
DmaxMaverick
While fuel can be an issue, 4 years of doing nothing can, and often does, generate a whole laundry list of issues long before fuel goes sour (50 years or more, in my experience). Namely, sensors and solenoids, such as the wastegate solenoid, and failure of the vacuum pump and related plumbing (no boost = black smoke). A hardened, frozen or cracked diaphragm doesn't make much vacuum, nor does cracked hard lines or rubber hoses. It sounds like something(s) simple. You just need to find what nature has fouled in all that time.