I may have this problem as well. Definitely more noticeable in warmer weather. This has been brought up multiple times the last week or so and while it sounds like I may have the accumulator problem as well you can definitely help the issue by making sure you air filter is clean. Mine is not half as bad since I clened mine. Just a little more to back this theory up. Last week we had an interesting day here in Denver. In the morning and early afternoon it was sunny and warm and my surging was really bad. About 3 in the afternoon it dropped about 30 degrees in an hour and started snowing. The surging was barely noticeable. So would most agree that it also comes down to a breathing problem as well?
Mine was so bad before I cleaned the filter that even with the A/C off driving in stop-and-go traffic was a chore b/c low RPM's in 1st and 2nd caused major surge.
So, while the accumulator sounds like the primary culprit, those who are experiencing this may want to check the filter as well.
