I have a vacuum coming off my valve cover that has a smaller hose coming off of it and I don't know what the smaller hose connects to need some help!!!

 

See:

https://www.jaguarclassicparts.com/u...e-supercharged






It is hard to tell from the drawing, but the small hose in your photo (plugged with a bolt it appears) connects to a nipple at the top of the throttle body supercharger adapter assembly (item 1 in the diagram). The nipple can't be seen in the drawing, but it is behind that "hump" on the top of the assembly.

This is part of the crankcase ventilation system, and unfortunately ingests a large amount of oil during part/closed throttle conditions, and dumps it right behind the throttle body butterfly, coating it all with oil. This causes the inevitable sticky throttle condition that requires occasional (every few years) cleaning which is a royal PITA on the SC cars (I'm doing it now).

Some people have chosen to just plug that hose as yours is to avoid re-oiling the TB, reportedly with no ill effects. I'm considering the same. I'm definitely installing an oil separator catch can regardless though.


P.S.

It's the broken sledge hammer lodged near the supercharger that has me worried!
.

 

Thanks for the info I will take a look at it the sledge hammer is for when I get frustrated...

 

My 1996 XJR starts up and runs good until it warms up good and then it starts misfiring and blowing black smoke when I press on the accelerator anyone have any ideals about what could be causing this?

 

If the engine runs well until it warns up, I would suspect the oxygen sensors. The engine ECU only uses the signals from these two sensors once the engine is partly warm. The sensors are prone to fail on these cars at this age or circa 100,000miles