In 1992, Nissan offered two different engines, the GA16DE and the SR20DE, for the Sentra. The GA was a 1.6-liter, dual overhead cam while the SR was a 2.0-liter dual overhead cam engine. Setting the idle on your Sentra is an easy task that can be accomplished in less than 20 minutes in your own garage.
Park the vehicle and set the parking brake. Run the engine at normal operating temperature, race the engine to the between 2,000 and 3,000 rpm a few times under no load. Allow the vehicle to return to its standard idle.
Open and secure the car's hood. Mark the crankshaft pulley, located in the engine compartment, with a bright yellow paint pen. Start the engine and shine your infrared light from the tachometer on the yellow mark to record the idle rpm speed.
Disconnect the throttle valve switch at the throttle body assembly after turning off the vehicle's engine.
Re-start the engine. Check and record its idle speed. Idle speed should be within the specified rpm; GA16DE engine: 650 rpm for the automatic transmission; 800 rpm for the manual transmission; and for the SR20DE engine, 800 rpm for either automatic or manual transmissions. If the specified rpms are not within these parameters turn the idle adjusting screw at the throttle body until it is at 800 rpm, then race the engine to 2,000 to 3,000 RPM a few times under no load. Allow it to return to idle and re-check the idle speed adjustment. Once proper idle speed is reached, turn off the engine. Reconnect the throttle valve switch.
