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Q: Car randomly hesitates

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My car has a mileage close to 130,000 miles. Lately it started hesitaitng. It happens randomly. It would ocasssionally hesitate when I'm driving for a while, while other times it hesitates when I start the car and apply the gas pedal. It is as if the gas is coming to the engine with a delay. I recently went on a longer trip and after about 80 miles, it started hesitating. It did it several times during the trip, while I was driving around 75 mph. The car would decrease the speed for a few seconds while I was driving at the mendtioned speed with my foot on the gas pedal. Then it would gather speed. The dealer couldn't solve the issue. There are no error codes and the car hasn't stalled at all. What should I do?

A: Hello. There are a few things that may expl...

Hello. There are a few things that may explain why you are experiencing a hesitation problem with your 2002 Lexus SC430. However, it is very difficult for any mechanic to diagnose an intermittent condition. Sometimes they need to worsen before they can properly be diagnosed.

There are a few known possibilities for your issue. If the spark plugs and/or spark plug wiring are causing an intermittent misfire condition, or there is an intermittent problem with the fuel injectors, you may experience some hesitation when accelerating or when pressing down on the accelerator pedal. If the mass airflow (MAF) sensor or the throttle position sensor is faulty, this may cause the hesitation problem you are experiencing - however, a Check Engine Light is usually accompanied with a problem such as this.

Another possibility, and perhaps the most costly, is that there may be an intermittent problem with the car’s computer, in that it may not be sending the proper signal to the fuel injector like it should at all times. This type of problem is not common, but it cannot be discounted. Have a certified technician, like one from YourMechanic, assist you with diagnosing and repairing your vehicle's acceleration problem.

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