Mechanics

IDLING HIGH AND SOMETIMES VERY LOW

1995 Toyota Carib

Engine Performance problem
1995 Toyota Carib 4 cyl Four Wheel Drive Manual 112000 miles

My engine idling is sometimes very high above 1.0 and sometimes goes low and engine wants to stall.

I have changed Distributor, vacuum sensor and plugs but problem still persists.

Drivability - Car wants to hesitate at slow speed. Gear No. 2

Please advise.
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Pkmusila
May 25, 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
May 25, 2009.


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