<strong>Fuel Pump</strong><br />So it isn't really a sensor, nor does the computer rely on it for input as to how the engine is running. What it does - and does well - is provide the high-zoot, fuel-injected engine with the proper volume and pressure of fuel that is required to run. It is located in the fuel tank (go figure), and a common misconception on the fuel pump is that it is either all or nothing. Well, consider that myth busted. The fact of the matter is that a non-H.O. engine needs to see 35-40 psi, while an H.O. motor needs to see from 40-50 psi of pressure at the fuel rail. Consult your factory service manual for the specifics for your year, but suffice to say if you are running 5-10 or more psi under the specified value, the Jeep will buck, spit, sputter, and generally run horribly. Attach a fuel-pressure gauge to the port on the fuel rail and check pressure at idle, under load, and full throttle against specifications to make sure that's not the problem.