Common Rail Diesel Injector Test - what does it mean?

wynanddb

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Common Rail Diesel Injector Test - what does the results mean?

Hi, I had the 5 injectors on my MB OM612 engine tested. Here is the results from the Bosch 815 test bench:
2010-06-08071844AM.jpg

Can somebody decode it for, I have no idea what the test is telling me?:confused:
2010-06-10065410sPM.jpg
 
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Varco

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I have not used this particular software before, so am having to guess about one or two of the symbols (particularly boxes 7/9/10). Anyway, here is my take…

For the ten boxes across the top:
Box #1 Engine speed/allowable variance
Box #2 Injected fuel quantity (=55.4)/tolerance (+/-4)
Box #3 Returned fuel quantity/tolerance
Note – I am think that the units for boxes 2&3 are mm^3/STROKE Eg how much fuel the injector delivers each time it injects.
Box #4 Injector current pulse width
Box #5 Rail pressure (=1350 bar)/tolerance
Box #6 Fuel supply and return pressure
Box #7 Time?
Box #8 Supply voltage
Box#9 Rail temperature/tolerance
Box #10 Fuel supply temperature/ tolerance
In each box the bottom figure is the result for the selected injector – the selected one is highlighted n blue (in the first illustration this is injector ‘A’).
Looking at the first picture it looks like for injector ‘A’ the only item out of spec is box #9, and this is only marginal. This problem is most likely with the test rig?
The second picture is more complicated. It is not clear if this is the other three injectors (to make up set of 5) – guess it must be. Main thing of note is the engine was not doing the same as the first test. The injected fuel quantity is very low (~2mm^2/stroke vs. 55.4mm^2/stroke), this is because the injector pulse width is very small. I’m not sure you can tell much from this test.
I would not say there is much to worry about here, but would be interested to hear from someone who uses this test rig.
 
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wynanddb

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Thanks! I subsequently sent the 5 injectors to another bosch agent for testing, hoping to recieve the results some time this week. I will post them once I have them.
 


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