Your GMC fuel pump will give you a few hints that it is ready to fail, such as halting, hesitation and lack of power during high-speed driving. You might notice 'lean misfires,' which is caused by an air/fuel mixture that cannot sustain combustion. A lean misfire means that unburned fuel is being passed into the exhaust system, which will boost your hydrocarbon emissions. Lean misfires also reduces your gas mileage. Often lean misfires occur because some kind of clogging in the fuel system. You might notice hard starts, which means you will hear the engine cranking but it will not start. And when the engine starts, it might give out. Finally, the fuel pump dies entirely - and your car dies as well. A fuel pump can be expected to last at least 100,000 miles until the lack of lubrication, heat and usage deteriorates the components. When you do replace your GMC fuel pump with a quality kit sold at our site, then take the time for some preventative maintenance measures. Change your fuel filter regularly. That easy and inexpensive measure will protect your fuel system from clogging from debris and rust. Do not drive with the fuel gauge on 'E.' An empty fuel tank will hinder the cooling of the fuel pump, since the fuel is used to cool the system.