1994 XJ6 ?'s

i have just got my first jag about a month ago ,94 XJ6,i only paid 2000.00 for her,has 107,300 miles and looks very nice ,now shes shakes bad when shes under load ,and the trans light comes on every once in a blue moon but then it goes back off,oh and the check eng. too but it has stayed on , and this all started within the same week ,i work on cars myself so i somewhat know about them ,but im ify with my jag,i dont want to make matters worse,i need a jaguar buddy lol us jag owners cant all be stuck-ups

with the ignition on and engine off depress the vcm buttom and read the obd1 fault code
this will give you a general cue as to what is malfunctioning