How's Holly?

Model: Haorui 1.8T

Mileage: 72,395 kilometers

Engine number: CEA

Car number: LSV

2. Description of failure phenomenon:

Fault phenomenon:

When the customer arrives at the station, it reflects the engine idling jitter, which makes it difficult to start. First of all, during the test run, it was found that the engine idling jitter was serious, it could not be accelerated, and it was difficult to start after flameout.

3. Failure Cause Analysis (1)

Possible reasons:

Throttle system failure

Fuel system failure

Ignition system failure

Timing system failure

Camshaft position sensor

Crankshaft position sensor

Fault code: P00 1 1

3. Fault analysis (2)

The fault code is as follows

Possible reasons for failure:

According to the meaning of the fault code, it is basically judged that the circuit is faulty and short-circuited to the ground, indicating that there is something wrong with the fuel injector circuit. Now, because the ignition is normal, there is no problem in checking the circuit. At this time, by checking the gateway list with the diagnostic computer, it is found that 09 Central Electric has two fault codes. As shown on the left in the figure below, the driver's door electronic system also has two faults as shown in the figure below:

4. Diagnostic and troubleshooting ideas (1)

When this fault code appears, the 92nd group of data in the data block is observed at the same time, and it is found that the theoretical value is completely inconsistent with the actual value. The oil pressure at normal idle speed is 1.6 bar, and the oil pressure at 3000 rpm is 3.4 bar.

4. The concept of diagnosis and investigation (2)

Normal vehicle data

Fault vehicle data

5. Determine the reason for the failure:

According to the above fault code and data block analysis, this car is not at the right time, so it should be disassembled for inspection. In order to confirm the number of teeth of this car, turn the crankshaft to the top dead center of 1 cylinder when disassembling, and mark the chain with paint. After marking, remove the chain and record the number of teeth between the three timing marking points. (For ordinary vehicles, the number of teeth between camshafts is 1 1, with 38 on the left and 39 on the right. There are 40 teeth on the left side of this car.

5. Determine the reason for the failure:

After replacing the relevant parts, install the timing chain and test run it. When reading 9 1 data, it is found that the theoretical value is inconsistent with the actual value, and the same fault code appears first.

5. Determine the reason for the failure:

Remove the timing chain cover again in the same way. At this time, I found that the timing of this car did not jump, and the timing was normal. At the same time, when inspecting the removed parts, it was found that the camshaft bearing seat lacked a return spring. It was not found during disassembly. Check the oil circuit, namely VVT, and find the fault point when checking the VVT control valve.

5. Determine the reason for the failure:

The fault point of this car is:

1. Causes of tooth jump in timing system

2. When installing the timing system, the VVT control valve is lost.

6. Thinking summary and experience sharing:

Maintenance experience sharing:

In the process of maintenance, strictly follow the standard procedures in the maintenance manual.

During the inspection, all relevant parts should be inspected to improve the qualification rate of primary maintenance.

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