Expert: Von Sudderth - 9/8/2005

Question
I have a 1991 Nissan Stanza XE with the 2.4 and am having problems with it idleing smoothly and have also had problems with it running too rich and then it will quit when the clutch is pushed in. I know that the engine too rich has too do with a sensor, but I am not sure which one it is. I don't think the sensor is bad, because it doesn't do it all the time, but I think it is a bad connection from the wire harness to the sensor. Do you know where the sensor is located that controls the fuel richness? Any suggestions and could you tell me where the idle control sensor is located at? Any help would be greatly appreicated.

Thanks,
Dean Burke

Answer
Dean,

You have a couple of issues.  The first is the engine is running too rich.  I would baseline the engine.  Since you did not say the check engine light is on I suspect the fuel filter needs to be replaced.  Second, the fuel pressure should be checked to verify that it is correct.  Next you need to change the plugs and verify they are black from the engine beiing over rich.  If the plugs are not too black and just gray then you probably have an issue with the air inlet hose being cracked and letting in un-metered air.  With all this said I would fill up with super unleaded and a bottle of Berrymans Chemtool fuel injector cleaner.  Now that all of this has been done I would clean the throttle body and adjust the idle.