It took me some time, but then I remembered: this is basically the down- tuned version of the more popular Disney movie "flight of the navigator". The key elements - boy helps spaceship and its sorta-sentient on-board computer and ends up years in the future - are the same, the only difference is that while in the Disney version the kid gets locked up in a lab and escapes with his alien buddy in this version he realizes what has happened and calls his alien friend to help him get back into the past before someone else notices so he does not end up in a lab. All in all though, while this version is less known and popular its nice as well and clearly worth watching.
Review of Navigators of the Space
