Hey Roger; Been there, done that.
I would create an export parfile and be sure to add
BUFFER=
COMMIT=Y

I usually set the BUFFER between 1000000 and 4000000, this is measured in bytes so 1 million is less than a meg ect...
This way you will commit every 1-4 megs rather than trying to import the entire table and then commit, which is the Oracle default.

Good Luck

MH