Blurr was long-established as one of the top racers on Velocitron when the Ark arrived there. Though initially consumed with racing like the rest of the populace, he sided with Override when the Velocitronian Civil War began.
The Blurr who appeared on Earth apparently left Velocitron in the company of a loader named Salvage, or else was a different one entirely from the one encountered by the Ark Crew. He claimed to be the "fastest racer in the galaxy" and a former winner of the Cybertronian 500. He and Salvage were the crew of a ship that crash-landed on Earth due to a meteor shower. Upon encountering several primitive humans, Salvage became determined to help them escape the shower, but Blurr was more interested in his own self-preservation and returned to their ship after lying to Salvage. Salvage later came looking for him, and upon finding him trying to launch the ship again the two ended up in a fight. A cave-in forced them both to go into stasis, and they were eventually awakened by Rescue Force Sigma-17.
After learning that Salvage had lost his memory of events following their crash-landing on Earth, Blurr claimed to have saved both him and the cave people tribe. After scanning an Earth race car for an Alt-Mode, his attitude began to wear on his fellow Cybertronians, and the ship's memory log revealed the true history of events. Despite this, the Rescue Bots offered him a chance to serve with them, but he ended up stealing their ship, the Sigma, and departing. However, upon receiving a transmission indicating that his comrades were in danger, Blur chose to return and help out. He and Salvage were then formally appointed as Rescue Bots, but reassigned to work in an area other than that of their mentors.
Blurr and Salvage would then join a group of Rescue Bot trainees overseen by High Tide, an old friend of Optimus Prime's. They later participated in a massive rescue operation when Griffin Rock, the adopted home of their fellow Rescue Bots, was teleported to the Arctic and had to be flown back to its original position.
On Velocitron Blurr was obsessed with racing and known for his rapid speech, but he was lucid enough to recognize that there were more important things.
The Rescue Bot Blurr was somewhat self-centered, putting his own concern and well-being above others. He was willing to lie in order to fit in with others, and slow to accept correction or take orders. Despite his poor attitudes in some regards, he has good intentions, and responds well to encouragement and the opportunity to be of help to others.