During the early 1980s, engine computer management systems relied upon a speed density fuel system that used inputs from a throttle position, engine speed, intake air temperature, and manifold absolute pressure (MAP) sensor to estimate the grams per second of air flowing into the engine.ĭue to the MAP sensor, the speed density system can compensate for variations in weather and altitude.
Armed with this knowledge, it’s entirely possible that you can provide an alternative solution to your customer’s problem.Īutomotive engineers know that 14.7 grams of air must be mixed with 1 gram of fuel to achieve nearly perfect combustion in a modern engine equipped with a catalytic converter. If you understand that a defective mass air flow (MAF) sensor can cause an extremely lean condition by underestimating the amount of air flowing into the engine, then you can understand how a defective MAF sensor can be mistaken for a defective fuel pump assembly. Let’s say that an amateur mechanic believes the P0171 “system too lean, bank one” trouble code that he retrieved with his code reader indicates that the fuel pump you sold him a month ago is defective.
0 kommentar(er)
