Several issues can cause this problem, either singularly or in combination.. Check the throttle body for dirt and sticky carbon deposits. clean the throttle body using a spray can carburettor/choke cleaner, and with the throttle valve held open, wipe out the bore of the throttle body with a solvent soaked clean rag. Make sure the throttle valve is not sticking any where in the throttle travel between closed and open.
Next, check the idle air bypass valve that is mounted on the top of the throttle body, for dirt and carbon deposits inside that can cause the idle air bypass valve to stick in an open position. Clean the inside of the idle air bypass valve with carb cleaner.
If the ignition timing is over advanced, (Specifies timing advanced is10 degrees Before Top Dead Center, with the in-line spark out plug removed from the spout connector housing, and with the idle speed set to the idle RPM shown on the emissions sticker under the hood, with the engine fully warmed up,) use a timing light to check and set the ignition timing to specification.
The throttle position sensor must be installed on the throttle body using the required method or the idle speed will likely be excessively high. Beginning with the battery negative cable disconnected from the battery, and with the throttle position sensor removed, place the sensor in position on the throttle body with the drive tabs on the sensor placed after the drive tabs on the throttle shaft, the holding the sensor on the throttle body, rotate the sensor counter clockwise to align the mounting screw holes in the sensor and the throttle body, Insert the sensor screws into the senor screw holes, into the threaded holes in the throttle body and tighten finger tight. Carefully center the sensor on the sensor screws, then tighten the screws firmly without over tightening. Reconnect the sensor electrical harness connector.
Inspect the throttle valve idle stop screw adjustment that holds the throttle valve open slightly, to prevent the throttle valve from touching the throttle body bore surface with the throttle closed, and the accelerator pedal unpressed.
796 views
Usually answered in minutes!
×