subject: Fuel injection pulse width in the public car fault diagnosis - the engine - Automotive repair and maintenance industry [print this page] The engine running for more than 5 minutes into the closed-loop control of the state, the oxygen sensor signal involved in engine feedback system. Turn off all electrical equipment subsidiary, measuring injector pulse width. Related Reading: Vehicle maintenance is particularly important the first time, full resolution sub-maintenance The new owner Note: How come people tell you that car maintenance 1, removing its oil pressure regulator vacuum tube, and a good block with a soft plug to prevent the intake system leak. At this time speed up, trying to block the return pipe, man-made increased so that oil pressure, if the feedback system to normal oxygen Sensor Normal injection pulse width reduction can be seen, the general reduction of 0.1 - 0.2ms, which is the computer on too thick mixture gas to amend the results. 2, causing a vacuum leak, make the mixture too thin. If the system is working properly, pulse width will increase 1.01 - 1.04ms, which is the ECU too lean mixture on compensation results. Old model of the Idle The role of oxygen sensors to be ignored, 1800r/min engine speed to the test. Pulse diagnosis with Idle Manifold 1, Hot car Idle during normal operation, pulse width is generally 1.5ms - 2.9ms. If the pulse width to 2.9 - 5.5ms is generally the phenomenon of the nozzle are blocked. New car run for some time, there are different levels of blocking the nozzle to reduce the fuel injection quantity, the computer that the air-fuel ratio increases (that is rare), idle down, we will amend the fuel injection pulse width, idle speed control correction signal to idle speed to target speed value. This cycle is repeated idle pulse width on the increase. At the same time the engine control computer will be here at this time of the idle speed control valve (stepper motor of the step, or pulse valve duty cycle signal) down to prepare for the next start storing reference. As the nozzle of each cylinder block level not the same, while the engine control computer to provide a fuel injection nozzle is the same width, resulting in engine work instability, Power Inadequate, poor acceleration, increased fuel consumption and other phenomena. At this point with a good washing machine can be basically solved the problem. Example: Superman era before cleaning pulse width 3.31ms After cleaning pulse width 1.70ms Should be noted, just a good cleaning nozzle loading, the engine speed convergence of natural increase, because the ECU fuel long-term result of the amendments, it has the data of learning and memory, thereby controlling idle speed, so that the mixture is too thick, Here is a re-learning process, because of the different models, study time are not the same, some vehicles can be a few seconds, some cars will need more time. 2, the nozzle has been cleaned the car if the idle pulse width is still large, have been identified through the data stream of air flow meter, air pressure sensors, oxygen sensors, and cooling water temperature sensor no fault, it is likely the root causes of failure is too low fuel pressure caused by this time need to determine the fuel pressure gauge or oil pressure pump controller failure.
Fuel injection pulse width in the public car fault diagnosis - the engine - Automotive repair and maintenance industry
