Martin Truex Jr. suffered engine failure during the Cook Out 400 at Richmond Raceway on Sunday and was not happy that his last full-time race at the track ended abruptly. While speaking to NBC Sports, Truex explained why his engine failed during the final stage of the race. “It hiccuped once down the backstretch and then started missing. It’s like it broke a valve spring or something, and then it just kind of self-disintegrated right there, self-destructed really quickly, Truex said. “I don’t know, it’s just one of them days.” Truex was then asked about the challenges he and his team faced on …