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What is your VIN number? I will check the original coding of your car.
Problem with W204 RPM Fluctuations
- Thread starterB0bby92
- Start date
What is your VIN number? I will check the original coding of your car.
B
WDD2040081F004364
B
A local mechanic completely rebuilt my TC. I went to him but was told the problem was in the fuel system, which I couldn't find.
This is a common reason - the regulator is sealed with a "cutting edge" (it is almost impossible to disassemble and install it in the rail pipe).
How do warm engine starts work? Try to track the pressure fluctuations on the rail in real values - it is advisable to download the graph.
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The common rail regulator was also replaced and was a simple job.
That's why I'm writing about this.
Note that Mercedes does not offer this regulator separately.
It is necessary to purchase the entire pipe together with the regulator.
Yes, you can buy the controller itself, but you can't replace it with a rail.
The entire system is designed in such a way that it is intended for only one initial assembly.
Take a look at the controller itself and you'll see why. The regulator seal is made in the form of a serrated edge that is pressed into the pipe body. If you remove the second assembly once, the seal will no longer be achieved.
On the forum you also mention another problem with leaking injectors - these things are interconnected - here it is either poor quality assembly or damage to the bearing surfaces of the engine head.
Note that Mercedes does not offer this regulator separately.
It is necessary to purchase the entire pipe together with the regulator.
Yes, you can buy the controller itself, but you can't replace it with a rail.
The entire system is designed in such a way that it is intended for only one initial assembly.
Take a look at the controller itself and you'll see why. The regulator seal is made in the form of a serrated edge that is pressed into the pipe body. If you remove the second assembly once, the seal will no longer be achieved.
On the forum you also mention another problem with leaking injectors - these things are interconnected - here it is either poor quality assembly or damage to the bearing surfaces of the engine head.
Download attachments
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Screenshot of Mercedes-Benz B2B Connect.jpg -
r.jpg
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No leaks after replacement. New regulator works the same as the previous one. Do you have a way to confirm that this is the problem? Maybe through XENTRY?
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XENTRY will only tell you if there is an electrical fault, such as a sensor not operating at the optimum voltage, sensor values out of range, open circuit, etc. XENTRY will not throw a fault code if there is a mechanical problem, such as improper installation, seal leak, etc. It can detect a mechanical problem if there is a sensor downstream of the leak that will cause the sensor values to go out of range, causing XENTRY to throw an error. In your case, since XENTRY is fine but you see an obvious problem, you can assume it is something mechanical.
You should review and confirm that blueabyss is right in this case. Leaks can occur days or weeks after installation because the system is under a certain pressure during operation, and if there is a small cut somewhere when installing parts, over time this cut will increase and cause leaks.
You should review and confirm that blueabyss is right in this case. Leaks can occur days or weeks after installation because the system is under a certain pressure during operation, and if there is a small cut somewhere when installing parts, over time this cut will increase and cause leaks.
I'm not entirely sure if XENTRY has a function in fuel leak tests. By monitoring the actual values, you can see the pressure fluctuations. But XENTRY is slow enough that you can notice it.
It can't record signals for playback.
Perhaps the pressure control valve test can tell you something - it's in the tests.
Firstly, the diagnostics are not designed for non-professional intervention. Replacing the pressure regulator - separately, without the "rail" tube.
I have an 8 channel oscilloscope (recorder). Do you know anyone who has one and can record it?
I connect individual channels like this:
1. Rail pressure signal.
2. Rail pressure frame (-) (for differential measurement).
3. PWM signal to pressure valve.
4. Current (A) of pressure valve.
5. PWM valve quantity signal.
6. Current (A) number of valves.
7. Current (A) of first cylinder for detection.
8. PRT50/150 pressure sensor for checking low pressure before high pressure pump.
This way you can see what the entire fuel system is doing.
A simple dual-channel oscilloscope should be enough to detect pressure fluctuations or some device like Launch, Autocom - just something that can record the actual rail pressure value.
I am convinced that the pressure is fluctuating - it is fluctuating because the control valve is leaking through the rail.
It can't record signals for playback.
Perhaps the pressure control valve test can tell you something - it's in the tests.
Firstly, the diagnostics are not designed for non-professional intervention. Replacing the pressure regulator - separately, without the "rail" tube.
I have an 8 channel oscilloscope (recorder). Do you know anyone who has one and can record it?
I connect individual channels like this:
1. Rail pressure signal.
2. Rail pressure frame (-) (for differential measurement).
3. PWM signal to pressure valve.
4. Current (A) of pressure valve.
5. PWM valve quantity signal.
6. Current (A) number of valves.
7. Current (A) of first cylinder for detection.
8. PRT50/150 pressure sensor for checking low pressure before high pressure pump.
This way you can see what the entire fuel system is doing.
A simple dual-channel oscilloscope should be enough to detect pressure fluctuations or some device like Launch, Autocom - just something that can record the actual rail pressure value.
I am convinced that the pressure is fluctuating - it is fluctuating because the control valve is leaking through the rail.
I found one test and photo on my PC when I was solving a similar problem on W211.
In DAS this test looks like this: if you look at the log, the desired current value (A) and the actual current value (A) are higher - why? The device tries to close the DRV but cannot because the rail is damaged by the assembly. That the current value is higher than it should be. Why? The unit cannot close the DRV because the rail is damaged.
I still remember how the tightness of the rail was checked.
0. Dismantle the overflow rail.
1. Disconnect the metering valve on the pump!
2. Disconnect the injectors!
3. Connect +12V to the DRV - this will completely close it.
When starting the engine, diesel should not flow out of the overflow rail.
In DAS this test looks like this: if you look at the log, the desired current value (A) and the actual current value (A) are higher - why? The device tries to close the DRV but cannot because the rail is damaged by the assembly. That the current value is higher than it should be. Why? The unit cannot close the DRV because the rail is damaged.
I still remember how the tightness of the rail was checked.
0. Dismantle the overflow rail.
1. Disconnect the metering valve on the pump!
2. Disconnect the injectors!
3. Connect +12V to the DRV - this will completely close it.
When starting the engine, diesel should not flow out of the overflow rail.
Download attachments
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6209-1185.pdf
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DRV.jpg