Ls 400 Throttle: Mind Of Its Own

paulanton · February 5, 2004

Hi,

Wonder if anyone can offer some advice & help with a problem that's just started happening on my 95k miles LS400 MK III.

When I lift off the throttle the revs don't drop, and sometimes increase! Then about 5 seconds later the revs then drop down, sometimes to idle, sometimes to a bit higher.

Any thoughts on how to cure this, it's a bit worrying to drive in traffic, and is going to take its toll on brake pads! Smoe problem with the throttle, the choke?

Any help would be very useful...

Thanks

Paul

ColinBarber · February 5, 2004

I would look at the throttle body. May need cleaning and lubricate the throttle return springs on the outside of the throttle body.

You need to check that the throttle is closing correctly when you take your foot off the accelerator. Get somebody to operate the pedal whilst you look at the throttle body butterfly.

flotsam · February 6, 2004

I take it the MKIII had an electronic throttle?

ColinBarber · February 6, 2004

I think only the MKIV has the electronic throttle? Just sounds like the butterfly is getting stuck open.

paulanton · February 9, 2004

Hi

Thx for the help. I cleaned and lubricated the springs this weekend: seems to have worked a treat!!

Ta V much

Paul

GreyBeard · May 3, 2004

did your throttle continue to work properly after the lubrication job? i did mine, but it came back afer 50 miles, so i suppose i've got to clean the throttle body, but i was curious how yours had gone.