1991 Suzuki


Bob Talevich

July, 27, 2008 AT 12:39 PM

Engine Mechanical problem
1991 Other Suzuki Models 4 cyl Four Wheel Drive Manual 70000 miles

what causes the fast idle, and how do I fix it? Had it to a repairman and did not help. I can do it myself if I know the steps. This is on my Suzuki Sidekick.

2 Answers



July, 27, 2008 AT 12:45 PM

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.


Bob Talevich

July, 27, 2008 AT 1:04 PM

Thank you for the suggestions. Is there a schematic so I can locate all these parts?

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