i have a 97 chevy suburban k1500 5.7l
im getting dark black and blue smoke from the exhust im not useing oil that i know of and it has become hard to start. there isnt any pil mixing into the coolant ive checked that, this suv has at least 150,000 mi. any suggestions i could really use the help this is a family suv 4 kids and a small dogso theres 7 of us so we need this beast running its all stock.
Your suv is running rich and burning oil. First, examine the spark plug. They likely need to be changed.
The causes, and cures, for running rich are numerous. A number of checks need to be done. The fuel pressure might be too high. So, check fuel pressure and the fuel pressure regulator. The engine coolant temperature sensor (and other temperature sensors) could be erroneous and causing excessive fuel injection. Measure its resistance and/or voltage.
A dirty engine air intake tract (idle air control valve, throttle bore and throttle plate) can lessen air flow into the engine combustion chambers. Clean with Throttle Body Cleaner.
Obtain, and use, the fuel control/engine management section of the repair manual (such as: Haynes; Chilton’s, etc.).