How to Prime a 6.7 Powerstroke After Fuel Filter Change

Since its introduction in 2011, the 6.7L PowerStroke engine has proven itself an outstanding choice for many owners. But like any new technology, the 6.7L has experienced some initial teething troubles.

These issues can often be easily solved. To do so successfully, one needs to know how to prime the fuel system after replacing a filter.

1.       Turn the Ignition Off

After experiencing emission and fuel system issues with their 6.4L Power Stroke engine, Ford needed something revolutionary in response. Enter the 6.7L, an engine which proved groundbreaking in many aspects – CGI block technology, reverse flow cylinder heads, air to water intercooling technology and 400 horsepower with 800lbft of torque were just some of the many key attributes this revolutionary engine offered.

Not an ideal engine, it was nonetheless reliable and should provide years of reliable service with proper care and maintenance. Though like any diesel, its issues could arise over time; most can be avoided through regular service visits and proper care.

First and foremost, inspect the fuel filter. Most fuel pump/injector issues begin here. If injectors are leaking or the pump doesn’t prime properly, your engine may sputter and not start. In most cases, loosening one screw and pushing on a plunger multiple times should solve this issue; referring to your owners manual can provide further details, though online search tools such as google can often provide answers tailored specifically for your vehicle.

2.       Turn the Engine Over

If your engine starts and then runs rough after replacing its fuel filter, it could be that its system needs to be bled. Bleeding works similarly to bleeding brakes: to do it properly requires installing a bleeder screw (or bolt) at various points throughout its line (one by one if applicable for 6.4L fuel cooler), as well as providing an adequate container to store primed diesel “blood,” plus an adjustable wrench of various sizes (see below for exact specs).

Open and operate the bleeder until bubbles stop erupting from injector pumps and fuel can be seen pouring out around it. Once this process has completed, close and tighten up the bleeder – usually it should take at least 6 cycles of cranking and priming before your system has been properly bled of air, freeing the fuel delivery system of any air pockets that might prevent starting your engine successfully – in order to ensure optimal operation as well as prolonging pump and injector life and wear and tear.

3.       Turn the Ignition On

Step two is designed to remove any air that may have entered the fuel system

during filter change. To do this, turn the key on and off six times without cranking the engine; this will purge any trapped air out of your system and allow your lift pump to refill it back up again.

If your engine still doesn’t start, drain and bleed the entire fuel-water separator (and possibly injection pump). To do this, consult your owner’s manual, but in many cases simply Google it to find instructions. It involves loosening a set screw and using the priming pump until fuel comes out clear of air-bubbles.

Try loosening and tightening the bleeder screw on the fuel filter or, for 6.4L Power Strokes, tightening and loosening the Schrader valve at the bottom of the cooler (located under the driver’s seat and bolted to a bracket connecting both turbos). Keep adjusting until straight fuel comes pouring out of your tank vent.

4.       Start the Engine

If you own a 6.7 Powerstroke and have recently installed a new fuel filter but it still won’t start, it may be due to air in the system. To bleed it properly and ensure optimal performance of your truck’s performance, consult its owners manual or search online for guidance; otherwise a quick Google search should provide all of the steps to bleed its system for your particular model truck.

Step two is to place the key in the run position and cycle it between run and off for 10 to 15 seconds, to prime the fuel pump to deliver fuel to CP4 injection pump for an initial short duration. Alternative Fuel System Priming Methods | Loosen the Bleeder Screw on your fuel filter (or unhook union nuts on 6.4L engines) and bleed the system, to rid of air and bubbles in your system and prime its injectors before closing your injectors and starting