In Comtrade, data availability is based on commodity classification. From your question, it seems that you query only HS2002, which started in year 2002. If you want to query longer time series, you have to use older classification. But first, you have to know what commodity codes to be used in previous version of HS. For an example, HS02 codes ...

I am having MAJOR difficulty getting hold of coffee data (EU coffee imports, and the key countries from which it imports coffee). COMTRADE has given me this data for 2002 onwards, but I ideally want to have data from 1985-2005. Does anyone have any idea of possible sources for this? Or is it available on COMTRADE and im just not accessing it ...