How do you adjust a carburetor on a 1987 Mazda B2000 it's running way too rich and fouling out the spark plugs?

Answer 1

Answer 1

More likely the problem lies with a faulty throttle position sensor (TPS) switch than with carburetor adjustments. Go to your public library and check out a Haynes or Chilton Repair Manual for your vehicle. Chapter 6 will give you procedures on how to retreive the trouble codes to determine for sure if the problem lies with the TPS. You will also read the procedures for checking/replacing the sensor.

Answer 2 - Other considerations

Although answer 1 is perfectly good, there are a couple of other possible causes:

• Assuming that the mixture may not be over rich, it's possible that excessive wear of the "oil" rings on the pistons are allowing excess crankcase oil into the combustion chambers [cylinders] thus causing fouling.
• Another possibility is excessive wear on the valve stem "guides" which also can allow crankcase lubricating oil into the combustion chambers, also resulting in fouling. This second condition usually only occurs for a few seconds or a minute or two right after engine start-up, and will cause white smoke from the tailpipe for that few seconds or minutes. However, this problem continuing over an extended time can and will result in fouling.