Engine Performance problem
1998 Jaguar XJ8 V8 Two Wheel Drive Automatic 54600 miles
recently on a trip, I stopped for gas and when starting out to merge into interstate traffic, I could not exceed 40 MPH. Pulled over and shut car off, restarted and it was OK. It did it again after driving about 600 miles under similar circumstances and did not go off until about 10 miles later when I was suddenly able to accelerate to normal speed of 65 MPH. I have a 1500 mile trip ahead from Northern MN. Can I expect this to occur with more frequency? What is the code? Would appfreciate any help!