Question 176Motor Plants - QMED

The correct answer is B) fuel oil pressure. The illustrated device is likely a fuel injector, which is operated directly by the fuel oil pressure in the fuel system. The fuel oil pressure is what forces the fuel through the injector nozzle and into the engine cylinder, allowing the engine to function. The other answer choices are incorrect because: A) a rocker arm and push rod are not involved in the direct operation of a fuel injector, C) cam action is not the primary driver of a fuel injector, and D) excessively high combustion pressure would not be the direct operating mechanism for a fuel injector.