93 240SX Idling and Running Rough

[240SXCR]

My 93 240SX SE is idling and running rough. Tuned it up, including air filter, cleaned MAS and Throttle Body, replaced O2 sensor, and still have problem. Problem was intermittent, but now is constant. Any help will be appreciated.

[ChickenWyng]

I had the same problem recently. I replaced the fuel fliter and the pump and was still having problems. I ended up using Carb cleaner on the throttle body and put some Lucas fuel injector and fuel system cleaner in the tank ( The big bottle for about $10). After doing this I had to let it run for awhile before driving to push all the crap out of the lines and now it works fine. Hope this helps you out.

[Denko44]

just check your grounds to make sure they are all good and add a couple more grounds just in case... did the trick for me

[sk_8ersteve]

I had this same problem with mine. Is it a specific cylinder that is misfiring? Mine had the 3rd cylinder misfiring. Turned out that it was the fuel injector. Sometimes Fuel system treatment works but not if the injector is bad. They should test to about 13 ohm's I think if you know how to do that.

[RPM008]

Mine was running fine yesterday and today it feels like one cylinder in not working. The engine shakes a lot and runs really rough but smoothes out a bit over 2000rpm. Is this what you guys are talking about?I will try fuel treatment but how can I test the injectors. I pulled all the spark plugs and the all look the same.Any sggestions would be appreciated.Thanks

[240SXCR]

Found my problem, it was the Idle Air Control valve. Sprayed a can of throttle body cleaner in the top hose, basically fixed it. Still idles a little rough, but runs fine.