iwflsports.com is a participant of the Amazon associate program. If you purchase any product via our suggested links, we may earn a small commission. Learn more.

Top 7 Dodge Cummins Lift Pump Failure Symptoms & How To Repair Options

Knowing some Cummins lift pump failure symptoms could save your vehicle from damage. And this article will guide you through.

In doubt concerning the particular Cummins lift pump failure symptoms your vehicle is experiencing? Our in-depth review will be of immense help to you.

If you did not know, the lift pump aids in delivering fuel. And you can find it beside your car’s fuel tank. Meanwhile, through the utilization of a DC motor or vacuum, it draws fuel oil from its container.

After that, it passes it down to the carburetor bars to produce a spark. Finally, the engine will burn and start operation.

For many reasons, this device might be unable to pump fuel, thereby preventing your vehicle from operating. So, read on to know the different Cummins lift pump failure symptoms to consider.

Cummins Lift Pump Failure Symptoms

By knowing your Cummins lift pump symptoms, it will be possible to get a solution. Thus, with the right information, you can eradicate problems that may cause your vehicle from performing well. Let us find out the possible Cummins lift pump failure symptoms.

Some common Cummins lift pump failure symptoms include:

A delay in the engine starting

Generally, many vehicles experience this particular problem. If you have enough fuel in the tank, yet your car refuses to start, check your fuel pump.

Such issues arise due to the inability of the fuel pump to pressurize the engine piston for operation. Other things that might cause your engine not to start to include:

Low rate of fuel pressure

Anytime your vehicle is in operation, endeavor to check the amount of pressure it generates. Generally, Cummins engine has its specific pressure rate, which is 20-40 PSI.

Thus, if you notice that your pressure gauge is below the estimate, your lift pump is not pumping well.

Another way to determine low fuel pressure is to make sure that the tank contains enough fuel. From there, you can check whether it delivers it to the engine.

Low engine compression

Lack of sufficient pressure could delay the engine from starting. As such, it will be difficult for it to generate the required heat to ignite fuel. And the issue is peculiar in any vehicle whose engine has higher mileage.

Fuel quality

If the quality of your fuel is bad, it might spoil some internal components of the engine. For example, the injectors can fail, thereby causing a hard start.

Low cranking speed

You might probably experience low cranking speed during cold periods. Meanwhile, it has to turn over fast to enable the fuel pump generates pressure.

That is because the fuel pressure helps activate the injection. Therefore, the engine will have a hard start without the actual process.

Less supply of fuel

If you do not have enough fuel or your supply pipes are spoiled, hard starting is likely to occur. Besides, check for any blocked breather since it might create a vacuum, thereby drawing fuel back to the tank.

Top 7 Dodge Cummins Lift Pump Symptoms

Refilling of the tank too often

Whenever you are refilling your vehicle too often, check for lift pump failure. That may happen because it is not pumping the required fuel nor restore unused one. In that case, you might have to refill too often.

Fuel line leakage or cracking

A leakage or cracks in the fuel line could be a result of lift pump failure. And that is clear evidence whenever the oil is slightly falling off.

Vehicle making unwanted sound

Anytime your vehicle starts making noise all of a sudden, it may be a symptom of lift pump failure. If you pay close attention to your fuel tank, you might notice a squeaking noise.

Therefore, your lift pump is the problem, and you have to find a solution to it.

Engine splutter during accelerations

Most fuel lift pump failures occur even when the vehicle is still accelerating. However, the spluttering/jerking will be there, but it only happens while accelerating.

Vehicle high temperature

If you experience a rise or halt in the temperature of your vehicle, check your lift pump. Meanwhile, the problem might result due to its inability to pump oil. Therefore, you do not have to ignore the problem.

Loss of power

Some particular vehicles experience fuel lift pump failure in different situations. Usually, a fuel lift pump can still function well even when it is under stress. Likewise, an old one is not an exception since it can perform under certain conditions.

Due to heavy load carrying, trucks and vans can put the vehicle under stress, including other vehicle parts. And that could cause extreme failure to a lit pump or other components.

However, you may find it hard to climb steeper hills. Sometimes it can even be hard for the vehicle to undertake heavy-duty tasks.

As a result of all these, the vehicle will start to experience a loss of power. A car that loses energy willingly might be dangerous. That is because sudden surging is one of the symptoms of lift pump failures.

Due to wear and tear arising from prolonged use, the lift pump might face inconsistent resistance within its motor.

Black or Blue smoke

Sometimes a faulty lift pump can affect the injectors and fuel pressure. So, if you are not careful, they might be expensive damages. If you see black smoke, run a background check on the fuel systems and injectors.

On the other hand, blue smoke indicates that your engine is using more oil than fuel. A faulty lift pump will not allow the oil to mix with fuel, thereby causing blue smoke.

Solutions of Cummins Lift Pump Failure

  • If your vehicle refuses to start due to a faulty lift pump, you may have to replace it immediately.
  • When you refill your fuel tank too often, consult a mechanic to check your vent valve.
  • Engine splutters in vehicles is repairable. Thus, you can contact a mechanic to handle it for you or get a new one.
  • Moreover, if your vehicle makes a spluttering noise when the speed is high, you need a new fuel pump.
  • With a repair kit, you can fix leakage or crack in your fuel lift pump.
  • If your vehicle has a high temperature, put your heater on. After that, switch off the engine and lift the hood. You will notice the engine cooling off gradually.

How to Test Cummins Lift Pump?

To test the performance of your lift pump, switch on the start function ignition key at once.

Even though the engine will not kickstart, let it be and leave the key in the accelerating position. Note that the lift pump should be on for about 25 seconds.

You can test your lift pump in the following ways:

  • Remove the fuel pump two-wire connector.
  • Using a voltmeter joined to the two pins on the supply side, turn the key to crank. If it reads 12V, then there is nothing wrong with the lift pump and supply-side fuse.
  • After that, start the engine cold.
  • Off the engine and key before taking the fuel pump side of the connector.

FAQ’s Cummins Lift Pump Failure Symptoms

How will I determine if my lift pump is bad?

If your engine was still functioning before a change in the fuel filter or opening the fuel line was made.

And it is still not operating or stopped halfway during operation even when the lift pump is running. Therefore, you might be having a faulty lift pump.

What are the Cummins Diesel lift pump problems and the solution?

Solenoid

Usually, every Cummins lift pump comes with an electronic solenoid on the pump’s back. Meanwhile, the solenoid receives an electric charge to release an actuator that tells it when to open or close.

However, if the solenoid is shorted, the pump might malfunction.

Solenoid damage solution

If your solenoid valve neither opens nor closes well, check your power supply. Besides, if there is a leakage, look out for spoiled or worn seals or membranes and replace them.

You can also check whether residues are inside the valve orifices. Take time to clean it properly until the pipes are clean.

Sometimes the solenoid might damage due to coil burn out or cold with the power on. In this case, check if you have the right power supply to distribute heat by ventilation.

Use a new coil and install it immediately. But do not use it if you do not mount it on the valve.

Coupler

Simply put, the coupler is a gear that binds the fuel lift pump to the gear train. And it permits the pump to create a vacuum that aids in drawing fuel from the tank.

If the coupler damages or breaks, the fuel system will be unable to maintain the proper suction. And drawing fuel from the tank will be a hassle.

Coupler damage solution

Shut down the vehicle. After that, look out for misalignment problems and check the coupling insert to determine whether it has wear and tear. Try and use a double-cardanic spacer coupling for a replacement.

Overloading could be the primary cause of coupling failures. In that case, put off the engine, check shaft sizes and how they fit. After that, tighten any improper fit using a liquid hardener so that bolts do not back out.

At times, torsional vibration might cause coupling problems. So, you have to shut off the vehicle and check for damages.

If the problem is due to torsional vibration, contact the manufacturer to carry out an analysis. Above all, tighten all coupling bolts to fit well.

Seal valve

Most Cummins lift pumps are shaft-driven. Whenever the oil seal within the pump starts leaking, the pump will not function at the right setting. However, an ultra-low sulfur fuel or using improper fuel additives can cause seal leakages.

Seal valve leaking solution

  • First, use an oil stop leak additive to fix the problem temporarily. Through swelling, the seal may stop leaking. Moreover, another method is through adding a high mileage motor oil to reduce or stop leakages.

What can cause my fuel injector pump to fail?

First, a dirty fuel in the tank can cause your fuel injector pump to stop operation. With time, the residue can settle inside and block the whole fuel injector pump.

Check the spray tip since it is the area that is prone to clogging. And it is where fuel leaves the injector to the combustion room.

What is the purpose of a Cummins lift pump?

Simply put, a lift pump provides fuel to the injector pump. From low-pressure angles to higher pressure pumps, it helps transfer fuel.

Is a lift pump similar to a fuel pump?

With modern fuel pumps, automobiles can run at higher speeds. Besides, they can improve fuel management by cooperating with a fuel injection system.

On the other hand, lift pumps help increase the level of fuel in the engine block. And that is achievable through suction creation and airflow management.

Can a lift pump operate all the time?

In short, it is the ECM that controls the run time of the lift pump. And it can operate for a predetermined time (for about one second on trucks) before shutting off.

Anytime you bump the starter without starting, the ECM allows the pump to run for about 15-30 seconds.

Can a lift pump add power?

Some lift pump manufacturers boast of superior water separation as one of the indicators to buy their product. But, a lift pump with a higher pressure can add power.

Verdict

Fortunately, some Cummins lift pump failure symptoms in this article apply to other company engines. Therefore, anyone with a different vehicle model can benefit from this review.

If you experience any lift pump failure signs, do not overlook them. Failure to attend to it on time can cause further issues.

So, look after your vehicle well by running maintenance often. You can take your car for a checkup daily, three to six months, or once a year.