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Q: Car misfires and fumbles during acceleration but regains pace. - 2003 Mercedes Benz C230

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My car seems to misfire and has trouble engaging when going uphill or accelerating when entering freeways. Last night it stalled on me for approximately 30 seconds but returned to normal afterwards. I'm not sure if I'm having issues with my spark plugs, fuel filter, or fuel pump. Any advice or insight you could offer would be greatly appreciated.

My car has 163000 miles.
My car has an automatic transmission.

A: Hi! The symptoms you describe sound like a ...

Hi! The symptoms you describe sound like a misfire caused by ignition components. Running ok until a heavy load is put on the engine, then stumbling and misfiring is typical of an ignition-related misfire. Spark plugs, wires, or coils are the usual suspects, and would be accompanied by a Check Engine Light and misfire codes. A fuel pressure test would provide helpful diagnostic information to confirm adequate fuel supply. An experienced technician, like one from YourMechanic, using a scan tool would be able to look at data that provides clues on which way to proceed. From there, they will be able to diagnose the misfire condition and conduct proper repairs.

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