FISA had announced abrupt changes to the fuel regulations earlier in the year, aiming to align them with IMSA rules. Porsche and Lancia strongly objected due to their significant investment in the existing regulations. With the dominant Porsche works team boycotting the event, the race was considered wide open between Lancia and numerous strong Porsche customer teams. Bob Tullius had commissioned the new Jaguar XJR-5 for the IMSA series and entered two for Le Mans.
Run in excellent weather, the race was characterized by excitement and tragedy. Lancia qualified 1–2 on pole, but the event was hotly contested from the start. The lead changed fifteen times in the first 50 laps, with a half-dozen cars jostling for the lead. The Joest Porsche of former winners Henri Pescarolo and Klaus Ludwig was badly delayed by fuel-pressure issues in the first hour, dropping to 30th position. Going into the night, Bob Wollek's Lancia held a narrow lead.
At 9:15 pm, as dusk fell, the most serious accident occurred on the Hunaudières Straight. John Sheldon's leading Nimrod-Aston Martin veered off the road at the Mulsanne kink, ricocheted across the track, and burst into flames. A track marshal, Jacky Loiseau, was killed by flying debris, and Sheldon was airlifted to hospital with serious burns. After an hour behind safety cars for repairs, the race resumed. The Lancias soon established themselves 1–2 at the head of the field, ahead of pursuing Porsches.
The race was notable for a very large number of mechanical incidents, affecting almost every car and preventing any single car from establishing a dominant lead. Everything changed around breakfast time on Sunday. The Wollek/Nannini Lancia, which had led through the night, had a long stop for gearbox repairs. The JFR Porsche in second pitted, running on five cylinders. This left the Pescarolo/Ludwig Porsche in the lead, having charged back up the field after their initial delay. The American Porsche of Preston Henn was second, one of the few cars that had a smooth run. Pescarolo secured his fourth Le Mans outright victory, and Ludwig his second. The ailing JFR Porsche held on for third, while Wollek took the Lancia out in the last quarter-hour to finish eighth, the first non-Porsche finisher.
The winner of the C2 Class was the Lola-Mazda sponsored by BF Goodrich. Neither of the Jaguars finished, despite running in the top-10 for most of the race. Such was the attrition that the winner's distance was 11 laps fewer than that of the 1983 winner. It was also the biggest comeback in the race by a team after an early-race delay.
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