For Consumers & DIYers
Carter^® is the brand of fuel pumps dedicated to making fuel system service easier! To begin, it is necessary for you to fully understand your vehicle’s fuel system and its maintenance.

How Your Vehicle’s Fuel System Works
The purpose of your fuel system is to provide a constant fuel flow at vehicle system pressure to the engine. A fuel pump pushes fuel from the tank and sends it under pressure to the injectors, which spray it into the engine’s intake manifold. The fuel pressure is kept constant by a fuel pressure regulator. There are two basic types of systems: those that utilize a fuel return line and those that do not. In a system with a return, the regulator is located at the engine, on the injector rail. In a returnless system, it is located inside the gas tank as part of the fuel pump assembly. Keeping your fuel system properly maintained is vital to your vehicle’s performance and fuel efficiency. A poorly maintained fuel system will eventually cause rough idling, hesitation, weak acceleration and even stalling.

Keeping Your Fuel Pump and Fuel System Healthy
A fuel pump in a gas tank has to endure a harsh environment. For one thing, it’s sitting in gasoline all of the time. But other factors can take their toll as well: heat and cold and especially dirt and sediment. Here are some easy steps for keeping your fuel pump and system in good working condition:

• Don’t make a habit of driving with a nearly empty gas tank. Running out of gas is not only inconvenient, it can burn up your fuel pump since the pump relies on the gas flowing through it to cool it.
• Keep the gas cap tight. This helps keep dirt out of the tank and keeps evaporative emissions low.
• Regularly inspect the gas cap’s rubber flange for cracks and breaks. A good gas cap seal keeps gas fumes from leaking into the atmosphere.
• Always run a good quality fuel.
• Use fuel with the recommended octane level for your vehicle.
• Have your fuel filter checked regularly, and replace it if necessary (typically every two years or 30,000 miles). Follow the schedule in your vehicle owner’s manual.
• Regularly check your fuel hoses and lines for cracks and leaks.
• The occasional use of a quality fuel additive will help keep your fuel system clean and the injectors from clogging.
• If you ever replace your fuel pump, make sure you have the tank cleaned.

1 - FUEL TANK
The role of the fuel tank is pretty simple: storing fuel until it’s needed. But today’s fuel tanks incorporate some improvements as well, such as baffles that keep the fuel from sloshing around the tank when you speed up or slow down. Tanks also have a fuel filler pipe, a fuel outlet line and a vent system.

2 - FUEL PUMP
The fuel pump sends fuel, under pressure, from the tank to the engine. In most vehicles on the road today, the fuel pump is electric and is usually installed in the fuel tank. Older cars have a mechanical fuel pump attached to the engine or an electric pump on the frame rail between the tank and the engine. Vehicles with diesel engines make use of either a mechanical or an in-line lift pump to feed fuel to the injector pump, or use no lift pump at all.

3 - FUEL FILTER
The fuel filter is a vital part of the system. It traps dirt particles, rust and other substances in the fuel line. The fuel filter is especially important in fuel-injected vehicles with electric fuel pumps (which is most of today’s passenger vehicles). Fuel injectors are especially susceptible to clogging, so it’s important that the filter be checked once a year and replaced every two years or 30,000 miles. A plugged fuel filter will also cause the fuel pump to work too hard to push the fuel past the blockage, leading to early pump failure. Most cars use two filters. One sits inside the gas tank and is typically called the strainer.

4 - FUEL PRESSURE REGULATOR
This device keeps the fuel at a constant pressure. When fuel pressure reaches system pressure, the regulator’s internal valve opens and allows surplus fuel to flow back into the tank. This especially occurs when the engine is idling or running at low speeds, and less fuel is required.

5 - FUEL FILLER CAP
What we commonly call the gas cap is more than just a lid. Its seal keeps fumes from the tank from leaking into the atmosphere and impacting the environment. Fumes in the tank are vented instead through a charcoal canister that traps fuel vapor. If, however, pressure in the tank reaches a certain level (which varies among vehicles) the filler cap has a pressure release valve that allows pressure to vent.

6 - GASOLINE
Gasoline is made of refined crude oil along with additives to improve performance and reduce emissions. For optimum engine performance and a healthy fuel system, when refueling your vehicle always choose a respected brand of quality gasoline, and be sure to select the exact octane rating your owner’s manual specifies.

Correctly Diagnosing a No-Fuel Problem
A lack of fuel to the engine may signal a failed fuel pump. But don’t immediately assume that the pump is the problem. Other issues may be causing the no-fuel situation. Review these easy-to-diagnose issues before you install a new pump.

Voltage supply issues may lead you to think the pump has failed. Check your fuel pump fuse/relay and body harness wiring. A bad ground or bad connection to your pump will render your pump inoperative.

Clogged external fuel filters and bent fuel lines can restrict flow. Obviously, even the best fuel pump can’t overcome restrictions upstream. Make sure these areas have been inspected, and replace the fuel filter if it is clogged.

Review the pump’s electrical connections at the pump flange and under the flange to the pump itself. Poor connections at these points cause a voltage drop (which cannot be diagnosed with a voltage drop test) that reduces flow and causes the pump to work harder. Repair any damaged electrical connections.

A new strainer must be installed any time a new pump is installed. Pumps may fail immediately or gradually if a new strainer is not installed with them.

Changing your fuel pump? Keep these facts in mind.

Your pump failed for one of three reasons: high mileage, tank contaminants or electrical issues. You can't remove the miles from your vehicle, but you can do something about the other two problems.