How to Adjust a Low Idle on a Lexus LS 400by Alibaster Smith
The idle on a Lexus LS400 is controlled primarily by the throttle. The throttle cable, specifically, controls the idle speed. If the cable is too loose, the idle will drop. If the cable is too tight, the Lexus will idle to high-decreasing fuel economy. Making sure that you have the proper tension on the cable will prevent the LS400 from idling too low and stalling.
Start the Lexus LS 400 and allow the vehicle to reach normal operating temperature. Then, check the idle speed. You should have an idle speed of between 500 and 800 RPM when the LS400 is at normal operating temperature. If you do not, raise the low idle speed to this range.
Open the hood and locate the throttle body on the back side of the engine.
Locate the adjustment nut on the throttle cable. The throttle cable is the cable that runs off from the throttle body. On the cable there is a nut that applies tension to the cable.
Turn the nut clockwise with a 10mm box end wrench to tighten the cable.
Check to confirm that the idle speed is between 500 and 800 RPM. Continue to turn the throttle adjuster clockwise until the idle is between this range.