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.

Answered by rasmataz
68 questions asked

I check the pressure of the fuel pump in the rail and this is 55 psi ( this is correct), I revised the fuel return line and this is NOT restricted. the fuel returns normally. I changed the oxygen sensor with a new one, believing that this was the problem, but with the previous one, also consumed fuel. I change the fuel pressure regulator by one new. I have been tested to the injectors and they have the correct injection level. here, There are two reasons I do not understand. I change the coolant temperature sensor by one new. HOW can be the coolant temperature sensor out of calibration? I not understand this part....and How can be Restricted air intake system? I have that revised all the vacuum hoses? please, thank you by you reply...

Response from currobar
2 questions asked

I check the pressure of the fuel pump in the rail and this is 55 psi ( this is correct), I revised the fuel return line and this is NOT restricted. the fuel returns normally. I changed the oxygen sensor with a new one, believing that this was the problem, but with the previous one, also consumed fuel. I change the fuel pressure regulator by one new. I have been tested to the injectors and they have the correct injection level. here, There are two reasons I do not understand. I change the coolant temperature sensor by one new. HOW can be the coolant temperature sensor out of calibration? I not understand this part....and How can be Restricted air intake system? I have that revised all the vacuum hoses? please, thank you by you reply...

Response from currobar
2 questions asked