My 1994 12v cummins completely quit building boost. When accelerating under 2k rpms it whines terribly. Turbo still whistles but barely, zero boost and tons of smoke. None of the rubber boots are blown off. Compressor wheel has a little play but I think it’s about like usual, and the end of the blades are a little warn out but I’m told that’s usual.

is my turbo blown? Intercooler?

i need it running soon so I can get to work and not get fired 🤦🏻‍♂️

 

Take off the intake side of the duct work, start the engine, and let it idle. Is the turbo spinning??

 

If it's an oil turbo (I believe the 12V are) see if you can move the shaft forward and backwards if you can the turbo is shot.

 

Have you tried to wiggle the turbo from/at the compressor? If there is lots wiggling the turbo is shot. You could do a boost leak down test. I made my own system. You need an ABS cap and drilled it for a schrader valve.
Here is a video showing what I'm talking about. A pressure regulator helps to keep the tester from becoming a Nasa launch vehicle.