Mechanics

MY CAR IS IDLING FAST

1999 Nissan Sunny

Noises problem
1999 Nissan Sunny 4 cyl Front Wheel Drive Automatic 127, 00 miles

MY FUEL INJETED CAR IS IDLING TOO FAST. WHAT DO I DO TO FIND OUT WHAT IS THE PROBLEM
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Azikall
March 21, 2009.



Too fast an idle speed. If an engine without computerized idle speed control is idling too fast and refuses to come down to a normal idle speed despite your best efforts to back off the carburetor idle speed screw or air bypass adjustment screw (fuel injection), air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine's vacuum fittings, hoses and accessories. It is even possible that leaky O-rings around the fuel injectors are allowing air to leak past the seals. Another overlooked item can be a worn throttle shaft and a defective idle speed speed control motor/valve stuck in the extended (high idle speed) position/throttle position sensor. Also the throttle plate could be binding in its bore and kinked accelerator cable, coolant temperature sensor might not be operating properly misleading the computer that the engine is still cold and computer throwing fuel at it raising the idle speed

Rasmataz
Mar 21, 2009.