Q: Car loses power occasionally

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Occasionally, when I drive my car, it seems as if it loses power and like there is a strain to keep running. After I turn it off very briefly and start it up again, it would run smoothly. What could cause this?

In most of these cases it is necessary to hear the type of engine strain you are describing to make a more accurate assessment. But based on your symptom that once the vehicle runs fine after it sits, this indicates a component that is not working at full capacity once it heats up, and works fine again after it cools down.

The first thing that comes to mind for this type of issue is a fuel pump that is not producing enough fuel volume as the pump warms up. One way to verify this is to hook up a fuel pressure gauge and monitor fuel pressure as you drive. If fuel pressure steadily drops after the vehicle is driven over time, this would indicate a weak pump.

Other possibilities include: ignition coil, engine ECU, relays, etc. Fault codes may need to be extracted from the engine computer to see if there are any other possible issues. One last thing to consider would be engine peripherals driven by the engine, alternator, AC compressor, etc. This tightens up once the component heats up.

You may want to enlist the help of a mechanic, such as from YourMechanic, who will be able to identify the type of engine strain you are experiencing and be able to diagnose and correct your vehicle’s loss of power.

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