Dirt in the fuel tank can be a major cause (Just like shown in the pics below). Over time, dust from badly filtered fuel at the pumps could accumulate and clog up the primary filter restricting free flow of fuel.
This guide is designed to explain the five most common signs of a failing fuel pump. That process begins with an explanation of the role and function of the fuel pump, which will help vehicle owners to understand the reasons behind a malfunction. I will detail common symptoms, everything from engine misfires to cars that won’t start. By the end of this guide, car owners will understand what symptoms to look for in their own vehicles.
1. The Engine Sputters at High Speed
The most common early sign of a problem comes when driving a vehicle at a consistently high speed. While traveling down the road, the car will run well for about 10 miles and then begin to jerk or sputter before returning to normal.
Many members of the driving community at times will mistakenly diagnose a sputtering vehicle as one with “dirty” gas, an almost empty tank or some other fuel-related issue. While that can be the case, it is not uncommon for a fatigued fuel pump to create this same symptom as it struggles to supply a constant stream of fuel to the engine at the proper pressure. The loss of pressure causes the engine to sputter.
2. Vehicle Loses Power While Accelerating
With a similar symptom to the previous, vehicles will jerk during acceleration from a stop. The car may produce a stalling sound and then accelerate smoothly.
What This Means
Once you take your foot off the brake and hit the gas pedal, a working pump increases the flow of gas or diesel to fuel acceleration. Because a malfunction starves your car of that increased flow, it doesn’t have the power it needs to respond to commands. Once pressure is restored, the engine is able to run smoothly, and the car takes off.
3. Sudden Loss of Power When the Vehicle is Under Stress
A car or truck is put under stress when the work needed to complete an ordinary task, such as forward movement, is somehow hindered by external forces. Generally, this occurs when climbing a hill or when hauling a load. If, when completing these tasks, the vehicle loses power, cannot accelerate, or begins to sputter, the fuel pump is a possible culprit.
What This Means
Generally, even an aging pump can maintain a steady stream of fuel and pressure when operating under normal conditions. These devices create resistance or fail when under stress, leading to power loss.
If your vehicle doesn’t lose power while driving, you may find it surges – accelerating suddenly with no drive input.
What This Means
Some may mistakenly blame this on the fuel filter, reasoning that it is not properly trapping dirt and rust. More likely, this surge is created because, as a result of age and normal wear and tear, the fuel pump has irregular resistance within its motor. This creates a situation where the pump cannot draw enough electricity to maintain the pressure needed for steady speeds and may “surge” with a sudden ratcheting up in pressure.
5. The Engine Will Not Start
The final symptom of a malfunctioning pump is also the most severe. Drivers who ignore the signs eventually will end up here, with a car or truck that won’t start.
What This Means
When a pump has malfunctioned to the point that the car will no longer start, this means that there is no fuel reaching the engine upon ignition. For that reason, drivers will hear the sparks try to ignite, but there will be no fuel to burn. To diagnose such a malfunction, check for a blown fuse and pressure in the fuel line, as the gauge should read 0.
An essential element of any internal combustion system, understanding what a fuel pump does and the different ways that it can fail can help drivers avoid bad situations with a car or truck.
The five most common symptoms of a malfunctioning fuel pump include sputtering at high speeds, loss of power during acceleration, loss of power to the vehicle while under stress, surging, and an engine that will not start. Understanding these symptoms and correctly identifying them early is the only way that drivers can avoid getting to the point where their vehicle will not start, stranding them and costing them a lot of money in repairs. Replacing a faulty fuel pump is not as simple as an oil change. People interested in changing a fuel pump without a mechanic should exercise caution, working in an environment where the temperature will not ignite gas fumes and using a premium pump assembly.
Also check the fuel filter and replace if necessary. Also check the injector nozzles if clogged and clean up if necessary.