I have a mazda mx6 1994 thats running rich, coughs and splutters and wont go up hills. Its had new distributor cap, rotor arm, sensors, timing belt, spark plugs, spark plug leads, and a service. Still made no difference. Help Please
Probable causes of an engine running rich are as follows: 1. Excessive fuel pressure can be cause by restricted fuel return line
2. Defective Oxygen Sensors.
3. Leaking injectors and fuel pressure regulator.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.