I have a 98 xjr with 97k and just ran a compression test today. Here's my results...

Front end
Driver side Passenger side
120 120
120 120
120 120
90 120

Any recommendations as to what I can do about these results? I feel maybe the car is lacking power i cant seem to break traction in a car rated at almost 400 tq. Car doesnt burn any oil or smoke or run rough or anything just low cmpression on the one cylinder.

 

have you checked your throttle cable adjustment?

search on here how to do it, it's very easy.

basically you connect a obdII scanner that can read your throttle opening percentage. plug in scanner to car, turn ignition on enough that the scanner works but do not start car. if it isn't reading 100% when you are flooring it, your throttle isn't opening all of the way. in the engine compartment by the throttle body there is a zip tie that you cut, then you can twist a square nut in its bracket until the throttle cable is tighter, replace the zip tie with a new one, and you should be good to go.

I did this on my car a while back, it was reading 93%, now it is 100%