How to Detect If Your Fuel Pump Has Gone Bad

February 27, 2020

Your boat’s fuel pump moves fuel to a cylinder to generate energy in the engine. When this part breaks or begins to fail, it can cause problems with running or starting your boat. Learn how to identify a failing diesel fuel pump so you can replace it.

Causes of a Failing Fuel Pump of a Diesel Engine

A broken fuel pump can have causes like:

– Too much water getting in your diesel fuel, making its way to your cylinder and overwhelming the filter

– Algae or fungi growing in your fuel tank

– Dirt, water or microbes in your fuel tank getting churned up and heading into your fuel pickup

– The use of improper or deteriorated fuel lines

– Failure to change filters when they get dirty

Fuel pumps can fail for multiple reasons, and a mechanic can help you find the cause if this part breaks down.

Signs of a Bad Fuel Pump of a Diesel Engine

The following problems could indicate a failed fuel pump:

– Lack of power: Your boat may idle smoothly, but it won’t have the power it needs.

– Smoke: You may notice smoke from extra gas if your diaphragm tears.

– Dead motor: Trying to push your boat to full throttle with a failing diesel fuel pump could cause your motor to die quickly.

– An engine that doesn’t start: Your boat may not start at all, or it may take longer to start than usual.

Bad fuel pumps can cause additional issues, such as acceleration problems. If you still don’t know the cause of your problems, a trained mechanic can help.

How to Test Your Fuel Pump

If you suspect you have a broken fuel pump, you can test it with the following techniques:

– Check your owner’s manual: Your engine needs the right psi to run. If the compression falls below your manufacturer’s specifications, your fuel pump won’t function right because of the low pulse pressure. Repair your compression problem first to see if it changes your fuel pump’s performance.

– Look at fuel line hoses and connections: Your connections from your tank to the fuel pump could have kinks or leaks that show signs of a bad diesel fuel pump. Loosen your in-line fuel filter hose clamps using a screwdriver, then check the filter to make sure there aren’t any obstructions.

– Use a fuel pressure gauge: Attaching a fuel pressure gauge to the pulse hose coming out of your fuel pump will help you show if your fuel pump is putting out the right pressure. Any reading below your manufacturer’s specifications means you probably have a defective fuel pump diaphragm or check valve.

Some of the issues related to fuel pumps can also have a different cause. Ask a mechanic for assistance if you can’t figure out the source of your problem.

Get a Fuel Pump for Your Diesel Engine From Diesel Pro Power

Diesel Pro Power has all the parts you need for your diesel-powered boat. Browse our selection of Detroit Diesel fuel pumps and Cummins fuel pumps to find a model that works. You can also call us at 888-433-4735 or contact our team online.

Fuel Pump for 4B Cummins Marine Engine

Fuel Pump for 4BT Cummins Marine Engine

Fuel Pump for 4BTA Cummins Marine Engine

Fuel Pump for 6B Cummins Marine Engine

Fuel Pump for 6BT Cummins Marine Engine

Fuel Pump for 6BTA Cummins Marine Engine

Fuel Pump for ISB 4.5 Cummins Marine Engine

Fuel Pump for ISB 5.9 Cummins Marine Engine

Fuel Pump for ISB 6.7 Cummins Marine Engine

Fuel Pump for QSB 4.5 Cummins Marine Engine

Fuel Pump for QSB 5.9 Cummins Marine Engine

Fuel Pump for QSB 6.7 Cummins Marine Engine