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Q: My 1993 GMC Sierra will barely go past 40mph

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Hey, i have a 1993 gmc sierra with 256k on it right now. And it will act like it will barley wanna go past 40 mph and when it does you cant hold a speed at all without the rpms going to 2,000 and sometimes 2,500

My car has 256000 miles.
My car has an automatic transmission.

This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this fails, this can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This is what causes the hesitation or loss of power you describe. This can also cause the engine to struggle to idle for the same reason. I would suggest having a professional from YourMechanic come to your home to diagnose your mass air flow sensor.

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