I have a 94 Chevy Silverado 4x4 6.5 Turbo Diesel and it seems to be blowing black smoke whether stepping on the gas or just regular pressure on the gas. The engine has been rebuilt and is still under warranty and just had a re and re on the transmission. Any help would be appreciated. Thanks.

 

Your fuel pump needs retimed. Like a gas car uses a distributer for timing, a diesel uses the fuel pump for timing. On My '94 6.5 TD, It had a timing mark right above the water pump that could be advanced or retarded to increase or decrease fuel. When They're blowing black smoke, They are running a little rich. A diesel runs rich to keep from burning itself up. If You notice a big rig ( 18 wheeler ) will blow more black smoke when climbing a hill. It over compensates the fuel under load to run cooler. The black smoke won't hurt anything too much, but it's really annoying.