Nissan Repair: Nissan Terrano SE SUV, rich fuel mixture, nissan terrano

Question
I just bought a used Nissan Terrano SE SUV, Gasoline engine. When starting up lots of black smoke is emitted and when idling the car is very irregular. Computer scan shows that the temp sensor is defect. I changed that but no result. Still the same. Any advice?

Answer
Hi Jerry -

Do you know what the code was for the computer scan? I am surprised you did not get a code for the O2 sensor as well.

Anyway, black smoke indicates a very rich fuel mixture burning. If the car is running rough at idle, you might want to check for vaccuum leaks or faulty injectors. The cold start valve could be malfunctioning as well. Somehow you are getting too much fuel in the intake manifold mixture.

Hope this helps -
aloha
calvin