Symptom: a 2009 Ford Fiesta sedan models, equipped with 1.5 L VVT inline four-cylinder engine and four-speed manual transmission, the total mileage of about 20,000 km. According to the driver to reflect the recent failure of the car appeared to accelerate undesirable, is to step on the accelerator pedal in the end, the speed does not exceed 100 km / h.
Troubleshooting followed the car, the first dynamic test. In automatic mode, when the speed reaches 100 krr by, if it continues to acceleration, the transmission will automatically downshift from 4 block down 3 block, block from 3 to 2 block, the speed gradually declined; in manual transmission mode , as in the four-speed position, regardless of how step on the accelerator pedal, the engine speed will not exceed 300011min. Then the static fault code scanner test, the slow step on the accelerator pedal, the engine speed up to 6600 r / min; slam the accelerator pedal, the engine speed up to only 4000 r / min.
Connection IDS, did not detect the fault code, then had to start from the test results. Under normal circumstances, if the engine speed to 6600 T / nùn, the engine control unit will control the oil off to play a role in the speed limit. Static test results can be seen from the oil off slow acceleration time is normal, but in the case of sudden acceleration can be seen as the oil off the timing advance. The fundamental reason for this situation should be enough oil supply, the direct cause of much of the oil pipeline blockage, such as for pipe deformation, fuel containing impurities.
Connect the fuel pressure gauge test, low speed when the fuel pressure is 4 bar (1bar = 100 kPa), normal; but only when hard acceleration fuel pressure 2.5 bar, low. Check the fuel pump to the fuel rail for the pipeline, and no abnormalities were found; check the fuel quality, also found no abnormalities. The fuel system for demolition washing machine connected to the fuel rail test, acceleration performance back to normal. Is it a problem with the fuel pump? Then replace the fuel pump, tubing connections for the good test, but the fault remains. This is strange, much deliberation, due to see the situation for internal tubing, so suspect the problem still lies in the supply tubing. The fuel pump to the oil supply pipe rails removed, the side with a piece of cloth wrapped around the tubing for, and then inserted into the high-pressure air gun for the other diagnostic tool for car side of the tubing. Hair felt something at the start of block, and later on smoothly, and will Jacobsson open and found a small piece of sponge, and has been soaked in yellow. Reconnect after a good test for the pipeline, acceleration performance back to normal.
Troubleshooting: The tubing for blockage after sponge removal of commissioning, troubleshooting.
Failure Analysis: for the pipeline is blocked sponge, or slow acceleration at idle, the engine fuel demand is not instantaneous, then the fuel reaches the fuel rail to meet the needs through the sponge, so in these two conditions, the engine can be work; but when hard acceleration, the engine instant fuel demand for larger, this time to reach the fuel oil rail through the sponge can not meet the need, so there will be acceleration trouble. For such a failure, mostly by observing changes of failure to identify the cause fuel pressure failure.
http://www.uobd2.net/wholesale/toyota-intelligent-tester-it2.html
No comments:
Post a Comment