Here is an interesting time line.
Scalia’s Supreme Court Seat Has Been Vacant For More Than 400 Days - The New York Times
According to data compiled by NY Times, the Senate has done something, even if it's just a filibuster, when a nomination has occurred during an election year.
George Washington nominated and had approved two new justices to court during his last year in office.
Even John Tyler, constantly opposed by the Senate during his tenure, was able to get multiple candidates voted on (admittedly rejected). At least that Senate would make a stand on something.
According to Wikipedia, Tyler actually nominated and had confirmed a Justice with less than a month left in his term. This happened in February - AFTER the election.
Andrew Jackson nominated a Justice on his LAST FULL DAY IN OFFICE and that Justice was approved.
Another post-election nomination was by Martin Van Buren
Wikipedia
Van Buren nominated Daniel during his last week as president, and Daniel was appointed as a Justice before his predecessor was even buried.
Rutherford Hayes and Benjamin Harrison both successfully nominated a Justice after the election.
If the Senate needs a precedent to do their job, here's a few. Geez, at least vote the nomination down.