2003 XK8 75K miles

I have not experienced this 1st hand, but my wife noted yesterday that the car was surging at around 30 mph. She also noted that the idle was rough. She noted that after it warmed up, everything seemd fine.

No codes being thrown.

My 1st thought is time to clean the throttle body, MAFS and Part-Load Breather.

Already grabbed the process and TSB from the stickies.

Sound correct?

 

I had similiar problem. What was suggested to do was to take both ends of the wire on the throttle body ( main feed ) and thoroughly wash all socket ends with electric cleaner. I did that and all cleared up.

That suggestion was from someone on the other side of the pond in England and worked wonders. Seems that the connections must be very clean to function perfectly. Worth a try.

 

Good approach. Also, make sure that the throttle body electrical connnections - especially the largest - seat properly and REMAIN SEATED. The little retaining clips on the inside of my large conector were broken and I didn't notice it. It would seat properly but slowly work itself loose creating electrical gremlins along the way.

I spent big money rebuilding the TB for what I now suspect was a simple connction problem. I carefully drilled through the outer connector shell and used a small stainless steel screw in a set screw type arrangement to firmly hold the male and female ends together. That immediately solved all sorts of operating issues!