July/August 2020

JULY/AUGUST 2020 AFTERMARKET 27 EYEBROW www.aftermarketonline.net pipework etc to find nothing wrong and then heading for the engine! Maintain pressure In my last example, I was able to help a fellow technician who had posted on a Facebook automotive group asking for some help with a Freelander 2. The vehicle was logging circuit fault codes for all four piezo injectors and wouldn’t start and then other times run and cut out. He had tested all four injectors electrically and they had passed all tests. He then checked the wiring between the engine control unit and injectors and again everything was ok which only appeared to leave a control unit fault. Another ECU was sourced and fitted and the fault will still present, much to his dismay. After further checks he decided to post on the group asking for some help and where he could be going wrong. It was at this point I decided to check for a TSB. Lo and behold, there was one for the fault code he was experiencing (LTB00277v2). The bulletin stated that this engine uses a 10-bar check valve in the fuel return pipework to maintain pressure on a hydraulic chamber inside the injector itself, which was critical for correct injector operation. It was possible, due to poor quality of fuel, wax or ice could form blocking the 10-bar check valve. This restricts the returning fuel leaving the injectors and causes the pressure to rise to over 150-bar. This in turn deforms the piezo actuator within the injector causing an electrical short to ground internally in each injector all at the same time. Some tests were done with this new-found knowledge and the valve itself was indeed blocked. A new leak-off pipe assembly was fitted and the vehicle was fixed. Imagine where the job could well have gone if this information had not been found again reinforcing what I have mentioned in this article. Printing and reading The wealth of knowledge and information that can be gained from manufacturer portals nowadays is brilliant. A lot of my learning has been doing by spending time printing and reading system operation and descriptions of different vehicles to get a better understanding of how it all works. This also includes known faults, as seen here, to save time when a vehicle comes into the workshop. Most websites are under £10 an hour to access, so well worth it in my opinion. The only downside can be navigating them all, as no two are the same unfortunately. While there you can also get factory wiring diagrams, service schedules, workshop manuals, technical specifications the list really does go on so next time you have some spare time or are struggling with a fault, consider signing up to one and do some self-learning or check there isn’t a bulletin available for the fault you have. www.aftermarketonline.net The wealth of knowledge and information that can be gained from manufacturer portals nowadays is brilliant ” Below: Range Rover Sport engine

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