Tips For Ford Diesel Misfire

Aug. 16, 2022

Ford F-Super Duty vehicles with diesel engines are experiencing some run-rough and misfire concerns. Here are eight tips on how to help fix the problem. 

Some 2011-2012 Ford F-Super Duty vehicles equipped with a 6.7L diesel engine built on or before 2-12-12 may exhibit a run-rough and/or misfire concern with or without DTCs P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 and P0308.

  1. Inspect all eight fuel injector hold-down clamps for a broken ear.

  2. If any broken ears are found, replace the clamps(s), re-seal the affected injector(s) and replace the injector-to-valve cover seal.

  3. Pry the injector-to-valve cover seal out of the valve cover using a screw driver. The new seal can be installed using a 22mm socket (rolling/pressing the seal in place).

  4. Inspect the fuel injector return hose connection at the injector(s) for damage and replace if needed at this time.

PART                         P/N

Injector hold-down clamp………BC3Z-9C334-B

Injector seal kit (1, 2, 7, 8)……...BC3Z-9229-A

Injector seal kit (3, 4, 5, 6)……...BC3Z-9229-B

Injector return hose……………..BC3Z-9A564-B

Injector-to-valve cover seal…….BC3Z-6C535-A

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

About the Author

Mike Mavrigian | Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of  specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.

Sponsored Recommendations

Tesla service, repair, and diagnostics

Keep update-to-date on how to maintain your customer's Tesla vehicles.

Tool Review: Ascot Supply 3/4" Drive 600 ft-lbs Split Beam Torque Wrench, No. 168-00600

Reviewed by Eric Moore, manager at DeMary Truck in Columbus, Ohio.

Diagnosing an engine misfire

Recognizing a misfire is the easy part; the challenge is determining its cause.

The ‘Iron Giant’

This technician spent two and half years putting together his ‘giant’ of a toolbox setup.

Voice Your Opinion!

To join the conversation, and become an exclusive member of Vehicle Service Pros, create an account today!