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Q: Takes three tries for engine to start and sluggish acceleration - 1990 Mercedes Benz 300CE

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When starting the engine, I have to turn the ignition up to three times before it will start. After it has started, the acceleration is sluggish. Then after driving a while it does become a smooth ride. Also, three times within the past six months while stopped at traffic lights, the RPMs kept going down until the car quit. I replaced the spark plugs. I also thought it might be a failing oxygen sensor, but the mechanic told me that my car does not use one, but he didn’t find the problem. I really love this car and want to find the cause of this. I have been changing the oil every 3700 miles. Can you determine for me what I need to do to find my car’s problem?

A: You will need to verify the fuel injection ...

You will need to verify the fuel injection pressure regulator is not leaking down or the fuel pumps do not provide enough fuel pressure and volume through the fuel filter. The hard start may be no pressure at fuel injectors at startup and then taking a few tries to build up pressure. If the pressure is low, then isolate the system to see if the regulator or fuel pump is bad. A certified professional from YourMechanic can come to your car’s location to diagnose the hard start and sluggish acceleration in order to have this corrected.

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