- Marty McFly: "You built a time machine... out of a Yugo?"
- Marcus Irving: "It's a sensibly priced car. And it doesn't quite travel through time. Yet."
- — Marty McFly and Marcus Irving during their first meeting
The partially working Yugo time machine.
The Yugo time machine was Doctor Marcus Irving's invention, a time machine comprised of a Yugo GX automobile that had to reach 88 miles per hour in order to time travel. It was uncompleted until 1986, when Irving stole Doctor Emmett Brown's flux capacitor, which allowed it to successfully travel through time.
History
During the Cuban Missile Crisis, General Groves and Colonel Lomax sought out Doc Brown, a scientist who had impressed Groves during his time on the Manhattan Project. Groves had thought that if anyone could invent time travel, he could.
However, upon arriving at the Brown Mansion on October 24, 1962, the pair had discovered that it had burned down on August 1st. Goldie Wilson let them know that most people in Hill Valley considered him an insurance thief.
They did not want to associate with a thief, so after the Cuban Missile Crisis had ended, General Groves and Colonel Lomax sought out another scientist to research time travel. Marcus Irving was given a lab and government funding to try to develop the necessary technology.
In January 1986, the United States government terminated the funding of Marcus Irving's time travel research, as his time machine wasn't complete since the final step had eluded him for the past 24 years. When trying to learn more about the government's research into time travel, Irving discovered that he had not been their first choice for building a time machine. Irving became jealous of Doc Brown being their first choice, and also angry at Brown for denying the offer and causing him to waste 24 years of his life. Thus, Irving set out to gather information on Brown.
Upon reaching Doc Brown's lab at 1646 John F. Kennedy Drive, he discovered it to be deserted. He conducted more research and learned of a close friend and assistant of Brown's, Marty McFly. Hoping to find out just how much success Brown had had with time travel, Irving went to Marty's house, only to see Emmett Brown in the DeLorean time machine reach temporal displacement, at the moment Doc left the canisters with Marty and his girlfriend Jennifer Parker.
At this point, Irving decided to try and contact Brown, leaving a message in Brown's second laboratory. On April 14, 1986, he came face-to-face with Marty McFly, who was also looking for Doc in an attempt to find out why his memories did not reflect the current timeline. He informed Marty that he had built a partially working time machine using a Yugo, and warned him that his conflicting memories could mean he could be erased once the current timeline caught up with itself.
Marty sent a message to Doc, who arrived shortly afterward. While Doc and Marty were talking, Marcus secretly removed the tires from the DeLorean, and used Doc's flux capacitor to solve his problem with flux energy, which was the final step needed for time travel.
He was afraid of altering time too much, so he had spent years driving around with the flux capacitor in his trunk, worrying that someone might steal it from him. He decided to take 2008 technology back to 1997 in order to make himself rich. Since he was afraid of altering time too much, he decided to only venture into the future in "baby steps", so he could better prevent any major changes to the timeline.
He built several doppelgangers of Marty and Doc using futuristic parts and sent them back to 1986. Some fo the Marty doppelgangers appeared soon after Irving had stolen the flux capacitor and kidnapped Marty. They tried to kidnap Doc as well, but he escaped in the DeLorean. It was still able to fly despite lacking tires, since the hover technology in the rims were untouched. One of Marty's doppelgangers held onto the DeLorean while it was in the air. This surprised Doc, as he thought that it would be very unlikely that Marty could have survived such a trip.
After fighting, Doc discovered that it was a robot version of Marty, with a metal skeleton and lifelike skin and eyes. Doc then returned to Marty to let him know that the situation was not as it appeared.