Ls 400 Revs

[v8rick]

hello all i wondered if someone could advise me here with an irritating fault on my mk3 ls400 sometimes though not always the idle takes a while to drop even after coming to a standstill it a stays around the 1000 rpm mark , this can also happen sometimes when the car is stationary a the engine is revved or the throttle blipped then after a few seconds the revs gradually drop to the correct speed and alls well is it time to clean the throttle body ? :D

[fatpieman69]

hello all i wondered if someone could advise me here with an irritating fault on my mk3 ls400 sometimes though not always the idle takes a while to drop even after coming to a standstill it a stays around the 1000 rpm mark , this can also happen sometimes when the car is stationary a the engine is revved or the throttle blipped then after a few seconds the revs gradually drop to the correct speed and alls well is it time to clean the throttle body ? :D

chances are that if its anything like my old starion or my mates primera its the 'throttle position sensor' it wasn't cheap though, about £200. gave the exact same simtoms as you've stated.

cleaning the throttle body and i asume sensors aswell will help.

[GoldfingerLS]

Hello dudes,

If your going to clean the throttle body thats cool. If your going to clean the throttle position sensor, you can just take it off and put it back on. It needs to be set in position with a volt meter and feller gauge. Check out the www.lexls.com website in the section where he cleans his TB, he explains how it is supposed to be done.

Let us know how you get on.

[jamesholden]

I always say start with the simples things first. Turn the A/C off and see if it stops doing it as the revs usually rise a bit when the compressor comes in on most cars to compensate for the extra load on the engine.