Vehicle failure: it is difficult to start the cold car in the morning.
According to the owner's description, the cold car is difficult to start. At most, it started a dozen times. After starting, you can't add oil by stepping on the accelerator, and the car will be normal after a while. In the hot car state, it can be started successfully every time. I went to another repair shop for inspection, cleaned the throttle oil circuit, replaced the spark plug, measured the cylinder pressure, and then went home. It was still difficult to start in the morning.
Maintenance steps:
The car arrived at the garage at noon. After the fat brother communicated with the owner, the owner said that he was not in a hurry to use the car now, but the problem must be checked clearly. Don't go back and start over.
Old people drive out, and they don't usually run.
The engine has also changed gas, and the car with changed gas often won't start. Mainly because of the mixed combustion of oil and natural gas, it is difficult to start, but this problem is generally difficult to start a hot car.
The car was left overnight, and the local temperature was MINUS 4-5 degrees in the morning. Brother Pang tried to start it several times, but the battery was dead. The engine feels about to start, but it still won't start.
Using the computer to read the channel number 00 1 and observe the data stream, Brother Pang found that the engine water temperature signal was actually 23 degrees, while Brother Pang's current local temperature was at least 0 degrees, so this water temperature signal must be abnormal.
We found the water temperature sensor.
Take it down and check it. The inside of the water temperature sensor has rotted.
Four-wire system
After unplugging the water temperature sensor, the computer shows that the water temperature is MINUS 40 degrees, which is normal by default.
A 2005 Passat B5 just parked in Pongo's yard. This car is the one that spontaneously ignited inside not long ago. Brother Pang removed the water temperature sensor and replaced it with a field one.
The computer shows that the engine water temperature is MINUS 3 degrees, which is in line with the local temperature of Pangge.
After replacing the sensor, Brother Pang started the car with a motor.
Although the car started, it needs to be observed and tested whether the fault is finally solved. At noon 12, at 6: 00, at night 1 1, at 7: 00 in the morning, the car can be started at one time.
Pang Ge concluded: This Passat site water temperature sensor adopts 4-wire system, and two wires are connected to the engine computer to provide water temperature signals for the computer. There are two wires connected to the instrument, but the water temperature of the instrument shows normal. As we all know, when the cold car starts the engine, the mixed gas is thick, which is beneficial to the engine start. As the engine water temperature rises gradually, the computer will automatically correct the fuel injection amount of the mixture. The water temperature sensor signal obtained by the engine computer of this car is 23 degrees, which is 20 degrees different from the actual temperature. The temperature difference of 20 degrees makes the signal obtained by the computer hot, and the default fuel injection quantity of the computer is thin, which will make it difficult to start the cold car. Then the hot car starts very neatly and easily.
Friends who like it can pay attention to it, and there will be more car knowledge to share with you later.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.