The McLaren team was thrown into crisis mode with less than an hour to go before the start of the Italian Grand Prix in Monza.
Jenson Button's MP4-28 failed to start properly when it was fired up on Sunday morning, and further investigations tracked down the problem to an issue with the car's complex fuel system.
TV cameras caught the McLaren technicians busy at work on Button's car, pulling it apart to gain access to the fuel pump located deep underneath the bodywork.
McLaren sporting director Sam Michael told Sky Sports F1'
s Ted Kravitz that this is the sort of repair that would normally be done overnight, rather than a matter of a few minutes just before the race, and that it was touch-and-go as to whether the car would be ready in time.
The car needed to be fired up and out of pit lane before 13.45 local time if Button was to be able to take up his ninth place on the grid for Sunday's race; otherwise, Button would have to start from the pit lane after all the other cars had gone past.
However, the McLaren team managed to get the car into a usable state and out of pit lane in plenty of time, with further work being planned on the starting grid in the remaining time before the formation lap.
For further updates from Monza, check out the Crash.net live commentary pages.