85 300d hesitation/surging above 3k rpm

[popimor]

When accelerating quickly (almost floored) my 85 300d has started to lose power every second or less and then put power on again above 3k rpm. Any ideas on what I should check first when I get home? Vacuum is fine in terms of shift quality. I am assuming turbo or fuel system related.

Interestingly when pretty cold out (50 degrees), and when the car was cold it did not exhibit this problem on my second trip today. As soon as it was warm it started up again. Thanks for the advice in advance. There is definitely a wealth of knowledge here.