OK, i got this 1989 5 speed Mazda b2200 pickup like 6 months ago. carburetor recently rebuilt, changed pcv valve, plugs and wires recently changed, lifters replaced as well.
my problem is when i start my truck and let it warm up, it makes a black stain on the ground from the tailpipe and smokes with a slight bluish tint when i rev the engine. i also have to add a quart of oil every fill up, also when I'm at higher speeds and i let off the accelerator i get an extremely loud or sometimes dull backfire. plus i don't get very good gas mileage, maybe 17 mpg. i thought it would be better since its a light weight 4 cylinder vehicle.
my question is, are these problems related, and what do you pros think it is, so i can get it fixed?