Mercury Grand Marquis engine races at start-up and revs in reverse with ignition delay on Mercury Grand Marquis

Submitted by 1990 Grand Marquis · Jun 23, 2025
Published by RepairPal

Problem overview

Some Mercury Grand Marquis owners report experiencing engine racing at start-up and revving in reverse, often accompanied by an ignition delay. These symptoms may be attributed to issues such as incorrect engine timing, which can lead to excessive revving and erratic behavior. Additionally, transmission problems, including front pump failure, can cause delayed engagement in reverse and abnormal revving. Faulty electrical connections, particularly in older models like the 2003 Grand Marquis, are also reported to contribute to starting issues and irregular engine behavior. Furthermore, general engine problems such as stalling, misfiring, and hesitation at certain speeds may exacerbate these symptoms. Owners are advised to seek inspection from a qualified mechanic to accurately diagnose and address these concerns.

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Mercury Grand Marquis vehicles with this problem

Average mileage: 42,000 miles
(42,000 - 42,000)

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