i was driving on the high way doing 50 mph and the trans was working fine . i got off the highway and the trans shifted fine through the gears ,got home parked it and when i got in and left about 30mins later the trans wouldn't shift from 2nd to 3rd. it shifts fine from 1st to 2nd but wont shift in to 3rd it just stays in 2nd gear .is there a vacume line broke mabe? i havnt any idea please help! it a 1988 eddie edition with the 302 efi