# Bad Idle and Running Rich



## jsumpter (Jun 16, 2010)

My 1992 Nissan Pulsar GTI SR18DE has a rough idle and is blowing smoke. The person I bought the car off told me it needed new fuel injectors but I wanted to be sure before I payed the extra $200. My mechanic and the nissan mechanics say it is running rich which is understandable considering it is using more petrol than any car I have ever driven! Since I have got it I have replaced the fuel filter and the mass air flow (MAF) sensor with no change. However, when I disconnect the MAF sensor connection the car runs much better then stalls. This leads me to believe it is something to do with the MAF sensor wiring maybe? The car runs rough at low revs but seems to clear at higher revs and on the motorway. Could anyone please tell me what could be wrong with my car/ what I might need to replace?

Thanks in advance.


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## tlhingan (Jun 8, 2009)

It could be the injectors sticking open, try cleaning them first.
Could be the O2 sensor as well, test it.
Test your battery and alternator as well, and check your air filter.


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## jsumpter (Jun 16, 2010)

My mechanic doesn't think it is the injectors causing the issue but I've booked the car in for an auto electrician to look at it anyway. The last owner replaced the O2 sensor so I don't think that is the issue. Will get my battery and alternator checked by the auto electrician but any further ideas would be appreciated!

Thanks


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## rogoman (Dec 16, 2004)

You may have leaking fuel injectors. To test them, unbolt the fuel rail from the intake manifold and pull off the entire assembly. Keep the fuel hoses still connected and don't remove any individual injectors. Also keep the electrical connectors on the injectors. With the assembly now away from the intake, turn the ignition key to the run position WITHOUT STARTING THE ENGINE. Now observe each injector to look for leaks. There should be no drips.


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## jsumpter (Jun 16, 2010)

Yay, I've fixed the idle problem!!! Turns out the MAF sensor was from an SR20DE and so I changed it to a SR18DE sensor and problem solved! It is still idling too high though so I'll fix that but very pleased to have this problem resolved! Thanks for the help guys


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## tlhingan (Jun 8, 2009)

Wrong MAF???
lol
No way we could have guessed that!


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