The two-time Daytona 500 winner, who lost two key crew members Wednesday when NASCAR penalized his team for using a fuel additive, said he had to be talked into racing by his wife and Toyota officials who are seething that Waltrip tainted their Nextel Cup debut.
"I didn't want to damage the integrity of the sport further by going out there and having people think, 'What's he doing out there?'" Waltrip said. "I came real close to not running today."
Waltrip needs to race his way into NASCAR's premier event in a qualifying race Thursday.
After his car failed inspection Sunday, Waltrip said he was devastated when his 9-year-old wondered why her father had cheated.
"That will hurt you pretty bad," Waltrip said. "I'm ready to bear all responsibility for what happened. You can't hurt me any worse than I am right now."
Waltrip's team was one of five busted for breaking the rules before the season opener _ the sport's most significant crackdown on cheating and a clear message the sanctioning body no longer will tolerate teams breaking the rules.
"It's been rough on everybody; we're here to celebrate a race," said NASCAR competition director Robin Pemberton. "Instead, we're busy dealing with all of this."
Waltrip's crew chief and team director were suspended indefinitely after a fuel additive was found during inspection. But Waltrip, docked 100 points, will be allowed to participate in Thursday's races that determine the field for the 500.
"I don't think we'll ever put this behind us, but we'll try to do better in the future," Waltrip said.
David Hyder, his crew chief, was thrown out of the garage and fined $100,000 _ the largest monetary fine in NASCAR history. Team director Bobby Kennedy also was kicked out. Scott Eggleston, who guided Waltrip to his 2001 Daytona 500 victory, will serve as Waltrip's crew chief.
Waltrip blamed an unidentified individual or individuals within his team, adding that no one had been fired.
"We haven't fired anyone, nor do we plan on firing anyone until we know what happened," he said. "We're aggressively trying to find out what happened."
He emphasized Toyota had nothing to do with his team's actions.
"This is my fault," he said. "You can't be skeptical of Toyota. You have to look straight at me."
Waltrip started his own three-car team this season with Toyota. The Camrys have struggled with speed since January testing. The cars he fields for Dale Jarrett and David Reutimann both passed inspection. Jarrett is assured a spot in Sunday's race because he's a past series champion; Waltrip and Reutimann must race their way in Thursday.
"We feel that Michael did a more than adequate job of explaining his feelings to NASCAR, to the fans and to Toyota about what transpired. Obviously, we're disillusioned," said Toyota motorsports spokesman Les Unger. "We share in the team's disappointment. But we feel that Michael is an individual of high character, and both he and we will move forward. We wish him all the best in today's qualifying race."
Waltrip's penalties came one day after the crew chiefs for 2003 champion Matt Kenseth, Kasey Kahne, Scott Riggs and Elliott Sadler all were suspended. All five drivers also were docked points in an unprecedented move by NASCAR, which never before had taken points before the season.
NASCAR officials would not reveal what they found in Waltrip's intake manifold, but a person with knowledge of the investigation told The Associated Press it was a property contained in jet fuel. The person requested anonymity because he was not authorized to discuss the details.
Although Waltrip is still trying to figure out exactly what happened, he acknowledged teams aren't supposed to mess with te fuel.
"In theory, it was supposed to hop the fuel up and make the car go faster," Waltrip said. "It didn't work. It's not supposed to be there. It's pretty plain and simple. You don't do those things. I thought everybody knew that."
Pemberton said only that the substance was not jet fuel itself.
The substance was found during Sunday's inspection. Adding the substance, described by NASCAR as an oxygenate, would boost the octane in the fuel, thus making the engine run better at higher horsepower.
Pemberton said the substance was discovered when a NASCAR official reached his hand into the manifold to feel for loose parts.
Some rival team members said they thought NASCAR should have taken away more points from Waltrip's team, because in a sport where cheating is common, tampering with the fuel is a major no-no.
The last penalty NASCAR issued for a fuel-tampering violation was harsher than Waltrip's. In May 2000, driver Jeremy Mayfield and team owner Michael Kranefuss each was penalized 151 points for a fuel-related violation found at Talladega Superspeedway.
"Throughout the garage area I think everybody knows you don't mess around with tires, you don't mess around with the engine, the restrictor plates," Pemberton said. "Those things are very taboo."
AP Auto Racing Writer Mike Harris and AP Sports Writer Chris Jenkins contributed to this report.