AVONDALE, Ariz. -- The Joe Gibbs Racing cars of Denny Hamlin and Kyle Busch had to change engines and start Sunday's Sprint Cup race at the back of the field, but Toyota officials said the motor problems were unrelated.
"Both were valve springs, but one was a mechanical failure and one was human error," said David Wilson, vice president of Toyota Racing Development. "There is no cause for concern heading into the race [Sunday] afternoon."
Hamlin's No. 11 Toyota team changed the motor Saturday after practice. Busch's No. 18 team had to change engines Sunday morning before the race
"Denny's engine had a part failure Saturday after only 61 miles of use," Wilson said. "We call that an infant failure, meaning it was defective. Kyle's engine had a problem Sunday morning because a new valve-spring wasn't installed properly. There was nothing wrong with his engine."
Wilson said those engines are completely different setups for restrictor-plate racing, which have no connection to this weekend's engines problems at Phoenix.
But JGR had numerous engine problems last season. Busch's No. 18 team had three consecutive races with engine failures during the summer. Busch failed to make the Chase.
"From Toyota's perspective, we were devastated about it," Wilson said. "We feel we cost Kyle a chance at winning the championship. Even though Kyle went to Richmond [last September] with a chance to make the Chase, he wouldn't have been in that position had he not had those earlier engine failures."
But Wilson said it's unfair to characterize the 2012 engines woes as only a Toyota issue. Wilson said most manufactures had engine difficulties last year with the switch to fuel injection.
"It was a tough year," Wilson said. "As an example, and I'm not singling anybody out, but Hendrick Motorsports [Chevrolet engines] had 18 engine failures last year. Jeff Gordon had four and Jimmie Johnson had four.
"There was a significant blip for every single engine builder last year, except one, Penske Racing. Penske was perfect for the second year in a row."
Ironically, Roger Penske's team no longer builds engines. After Brad Keselowski won the 2012 championship for Penske with Dodge engines, Dodge left the sport. Penske has switched to Ford and now leases engines for Roush-Yates Engines program.