Michael J. Fox took 3 BTTF films to connect with Christopher Lloyd

Great Scott! Michael J. Fox and Christopher Lloyd may have starred alongside each other in both Back to the Future and its immediate sequel, but it wasn't until the third installment of the beloved sci-fi film series that the pair really formed a strong connection.
It wasn't until 'Back to the Future Part III' that Michael J. Fox and Christopher Lloyd really formed a strong connection.

Back to the Future Part III (1990) - IMDb

Christopher Lloyd, Michael J. Fox have 'Back to the Future' reunion

Christopher Lloyd and Michael J. Fox charmed Back to the Future fans at New York Comic Con

Michael J. Fox & Christopher Lloyd Film: Back To The Future Part Iii; Back To The Future Part 3 (USA 1990) Characters: Marty McFly, Dr. Emmett Brown Director: Robert Zemeckis 25 May

Michael J. Fox took 3 BTTF films to connect with Christopher Lloyd

Michael J. Fox, Mary - Back to the Future Trilogy

Michael J. Fox, Christopher Lloyd & Mary Steenburgen Film: Back To The Future Part Iii; Back To The Future Part 3 (USA 1990) Characters: Marty McFly,Dr. Emmett Brown & Clara Clayton Director