[fusion_text]A rare Mitsubishi Pajero Evolution in our workshop recently for diagnostics . The symptoms were poor running , misfiring worst when cold and a very rough idle . The vehicle had already been worked on as is the case in most of our work. Most ignition parts had been substituted and the fuel filter had been replaced but the fault remained . Our initial diagnostics showed no fault codes present although these could have been erased . All available live data stream looked normal the ignition was tested on our Pico scope . We tested the basic mechanical condition of the engine testing engine vacuum and compression tests all proved to be correct the only clue to the cause was high hydrocarbon content when the exhaust emissions were tested indicating poor combustion. With customer approval we removed the inlet manifold and the injector rail . The injectors were tested in house in our Asnu bench and the results were quite dramatic very poor spray patterns and very uneven deliveries this confirmed our suspicions of poor combustion. When we removed the injector filters before cleaning there was a large amount of sediment inside . Ultrasound cleaning would not bring these injectors back to life , these injectors are very rare and we were faced with maybe trying a substitute or even having some built to match . After consulting with Asnu we decided to try a more radical approach which involved further cleaning and making up some adapters to enable us to back flush the injectors under high pressure . Several cleaning and flushes later we managed to restore the injectors back to a perfectly matched set . Rebuilding the inlet after fitting the injectors we ran the engine again and all was well restoring perfectly smooth running cold and hot . Injectors are the one thing that are not normally tested during diagnostics but are the component that carry out the most essential part of the process injecting the fuel in an atomised spray in the correct quantity.
injector deliveries initially..
sediment inside injector filters..
sediment back flushed from injectors..
injector deliveries after cleaning..
