When I floor on the gas pedal my truck picks up quick and gains speed quick until I get to 70-80 mph I loose power but not all of the power
My car has 89000 miles.
My car has an automatic transmission.
Hi there. Check the fuel pump and make sure that its working. Check the fuel pressure on the fuel rail and see if there is a loss of pressure. Its common for the fuel pump in the Silverado 1500 models to loose efficiency when there is a demand for a higher fuel pressure. Also, check the fuel pressure regulator on the fuel rail for any debris. I recommend performing an injection flush to clean out the fuel system and clean out the injectors. If you have an inline fuel filter, I recommend replacing the filter. Then retest the vehicle to see if the engine will have a loss of power at 70 to 80 mph. If there is still a loss of power, then I recommend replacing the fuel pump. If you need further assistance with a loss of power at 70 to 80 mph, then seek out a professional, such as one from Your Mechanic, to help you.