Autism is a developmental disorder, not a personality type. There are autistic people of a wide variety of personalities. Sure you can look at certain traits and correlate them to a certain MBTI or set of functions, but I really can't with MBTI people trying to give mental illnesses or other disorders a personality type. Their disorder inhibits certain mental functions. That's not their personality, that's their disease.
I had a guy in my college level literature class with Aspergers. He was super enthusiastic about literature and art, friendly, genuine, cracked jokes, and gestured wildly when he talked. It was only obvious he had Aspergers because of his jerky movements, his inability to regulate the volume of his voice and distinguish what was appropriate given the nuances of various social situations (which he asked the class to tell him immediately if he did or said something inappropriate so he could learn). Note how the manifestations of his ASD has nothing to do with his personality. No idea what his MBTI was.