MDEP Highlights

March 09, 2012

Today’s MDEP Highlight showcases a unique combustion diagnostic procedure that is performed using Mirenco’s MDEP Evaluation Equipment. The procedure is a fuel injector cutout test. In this procedure MDEP Evaluation equipment is used to measure an engines combustion efficiency while the engine is running with each injector cut out one at a time. This procedure allows a service technician to properly identify individual injectors that are no longer functioning properly.

 Identifying and replacing only those injectors that are needed is a significant improvement over the costly alternative of replacing all the injectors. Fuel injectors are a high cost replacement part and identifying only those that need to be replaced can save a significant amount of repair costs as well as down time while injectors are being replaced.

The images below show a good example of an 8 cylinder engine and how much of a difference in combustion there is when you cut out just one fuel injector at a time during the injector cut-out test procedure. When looking at these images remember that good combustion results indicate that a bad injector has been cut out. This makes for a quick and simple verification of fuel injectors that need attention. You can quickly tell that cylinders 6 and 8 have very low DPM numbers and no continuous trail DPM after acceleration. This means that injectors 6 and 8 when cut out during the test, no longer contribute to poor combustion results and the DPM results look much better. The results would indicate that injectors 5,6,7, and 8 should be replaced.