This past weekend my lovely wife and I decided to head down to Maine and get Chinese food. Just an excuse to go for a road trip. On the trip the Jag was running perfectly not a single hitch or miss anywhere along the route. However when I attempted to pass a transport I had to use the "super" button to get the jag to kick down and even then it seemed a bit anemic. So this morning I popped the hood to take a look and noticed a lot of slack in the throttle cable. I cut the cable tie holding the adjuster spun it 3 or 4 times until the slack was gone and oh my! Suddenly she has buckets of horsepower. It only took 5 minutes and one cable tie, I wonder how many other XK8s are only getting 3/4 throttle? I was able to smoke the tires with little effort! I wish I would have checked sooner.

 

I assume that this is right at the throttle body - it's hard to tell from the pic and I am not at home to look at the car? How much slop was there and did you just adjust it till it was taut? I will definitely have to check it out on my car...

 

From the front of the car it is to the right of the throttle body. Might be a bit different on yours being a newer vintage. The cable was sitting just a 1/4 inch above the guide and I adjusted it 1/2 turn at a time until it was snug. Feels like a new car, what a difference.

 

Newer cars have more of a fly by wire system. So, before you start adjusting, have some one hold the pedal to the floor with the ignition on but engine not running and observe the throttle plate position.