Can anyone point me in the right direction? My 1996 XJ6 vdp has started to not idle so smooth as of late and seems to not want to shift if I don't press the accelerator very hard.When I do press harder on the gas it works just fine. But tends to stay in first gear for a long time ,allowing the revs to climb up to near 4000 rpms when I don't press hard on the gas.Also the idle speed is rising and lowering from 900 rpms to 1100 rpms .Any idea's?My engine is the 4.0 six and has 210000 kms on it

 

Just a guess but have you traced all of your vacuum lines to see if they are intact?