Engine Mechanical problem
1988 Pontiac Firebird V8 Two Wheel Drive Automatic 150000 miles
I have a 1988 Firebird with 150000 miles. It is blowing black smoke when first fired up. Blue smoke when I lay on the gas. And when the car is at idle in park its fine when I put the car in drive my rpm's jump up and down. Plugs are new, wires are new, compression tested and was fine, no error codes displayed.
Blue and black smoke indicates burning oil. Oil is leaking into the combustion chamber and being burnt out the exhaust. You will have to tear the engine down to inspect the internal parts. Worn piston rings would be the most common to cause this but there is no way to tell without inspecting engine internally.