Hello. My 1996 XJS with the 4.0L has a problem with the throttle. The throttle body sticks when it is closed and takes a slight effort with either your foot on the pedal or your hand on the TB itself to move it. I am wondering if the butterfly itself is sticking on a ridge in the TB, or if it is the lever that the cable attaches to. Has anyone had something similar with this engine?

 

The throttle body on those cars are very particular. They get dirty very easy and most times if you clean them they are ok... they need to be adjusted properly too. There is a throttle stop that can be adjusted with a tiny Allen wrench...I cant think of the exact adjustment I think its .0002" to .0003" gap when the throttle is closed between the butterfly and the throttle wall. If that is not correct the throttle will stick closed...But be careful the adjustment Allen has locktite on it and it will round off easily...Your TPS might need to be adjusted afterward too

I'm sure that someone here has the correct gap adjustment on the throttle

From my experience if a good cleaning does not fix it the spindle bushing on the butterfly is worn and the throttle needs to be replaced

Hope this helps

 

Hello and thanks for the advise!!. I have seen the small throttle stop screw that you mention. I am going to give it a good cleaning and see what happens. I know there has to be a lot of carbon built up in the TB bore. The car was mostly driven on short drives and probably didn't up to proper operating temp too often. I don't think the bushing is worn as there is no play in that piece. It is just sticking when closed.

Rob

 

if you spray to much throttle cleaner dirt may get in to the shaft and cause it to stick open,if thats the case you could take it all apart and clean it would be a nice tim to replace the 2 seals,


if it stickes closed you can get away with just a good cleaning and setting the butterfly were the X mark it to .002",but remember the above statement

 

You know, I never did anything except drive it and the sticky throttle went away. Must not have been that bad to begin with.