Injector Testing Information Compilation

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Injector Testing Compilation

Note: This thread is in the Database Section. Please take personal vehicle problems and questions to other sections. Start your own thread.

There has been some good injector testing information surfacing lately. This is a compilation of the links I've noticed. It is in no particular order.

Fuel Injector Calibration [Condition] Is Important!
https://sprinter-source.com/forum/showthread.php?p=822233

I noticed the information that I asked for in another thread.

Injector Test Results Review Help -- out of spec for VE?
https://sprinter-source.com/forum/showthread.php?t=81018

I added it in blue here.

...

Added:
I see that the injection timing increases as the test graphs progress.

Are there names for the various tests?

Test #1 - 4.9 +/- 2.8 = LL – Idle

Test #2 - 1.4 +/- 1.1 = VE – Pre-injection

Test #3 - 17.6 +/- 4.2 = EM – Emission point

Test #4 - 58.8 +/- 5.5 = VL – Full Load
As a practical matter.

When the Sprinter engine is at typical operating loads, what is the typical frequency, fuel pressure, and pulse duration?

For decades I have used the climb up Lewiston Hill on "Lewiston Road" heading toward Niagara Falls as a test for engine power/condition. 45 mph posted speed limit. Within the lower 1/4 of the climb I set my cruise control. If the truck climbs the hill without downshifting I am fairly confident that power is still as expected. So far both the 2004 and 2006 present similar responses when climbing Lewiston Hill.

Maybe some of the injector test parameters which fail are not in the normal realm of an engine operating at, for example, 60 mph pushing the truck down the highway.

In other words, some of the failed testing parameters may only be experienced during minimal operating periods of time and therefore would have minimal negative impact on normal operation and service life of the engine.

The above comment assumes an engine that is running as expected and shows no other signs of deteriorated engine operating condition.

I don't know the answers. That is why I ask the questions.

:cheers: vic
Some additional discussion and info is here.

Injector Test Results Review Help -- out of spec for VE?
https://sprinter-source.com/forum/showthread.php?t=81018

Have a read over here.

https://gcldiesel.com/wp-content/uploads/2016/08/Common_Rail_Test_Results_205_Legend.pdf

It looks like the injector is actually opening faster than expected. This may be due to break in, or their machine could be a bit out of calibration. Personally I would not worry about VE much, as it mostly only impacts noise, and cold start smoke reduction. In fact some tunes eliminate the pre injection events (very short events prior to the main injection).

VL – Full Load
This point can be identified by a long actuation time, typically > 1400 µs and a rail pressure equal to the
maximum rail pressure of the injector. This is the only point where return quantity value from the injector
is measured while actuating. This measurement is taken in the nonballistic area of injection.
This test confirms:
• Maximum fuel delivery of the injector
o Low Power
o Over fueling
• Excessive return quantity
o Low rail pressure
o Hard start
VE – Pre-injection
This point can be identified by a very short actuation time, typically < 270 µs and a rail pressure equal to
the maximum rail pressure of the injector. This verifies the injector is able to consistently deliver fuel at
the minimum actuation time recommended. This is almost always at the beginning of the flat curve.
This test confirms:
• Injector components are able to react to the minimum actuation time
o White smoke
o Misfire
o Engine noise
o Aftertreatment issues
EM – Emission point
TL – Part load
These points can be identified by an actuation time, typically between 400 and 800 µs and a rail pressure
below the maximum rail pressure of the injector. The selection of the test points are manufacturer
specific. Typically they are looking for critical points in the engine calibration, especially in the ballistic
area of injector operation.
This test confirms:
• Specific points of the performance map as agreed upon by the OEM and Bosch.
o Mid-range performance
o Misfires
o Smoke
DSD SL 15-23
Page 5 of 5
LL – Idle
The name of this point is a bit misleading. While it is called “Idle”, it is not an engine idle point. This
point can be identified by an actuation time, typically between 300 and 400 µs at a rail pressure just
above the minimum operating rail pressure of the injector. This is to look at the frictional forces within the
injector and determine if there are any excessive forces on the moving parts of the injector that would
affect performance at moderate rail pressures.
This test confirms:
• Specific points of the performance map as agreed upon by the OEM and Bosch.
o Mid-range performance
o Misfires
o Smoke
Feel free to add new threads/links to this compilation. General questions are ok. Specific problem questions belong in other sections.

Added:

Injector Classify Program Code Coding Misc.
https://sprinter-source.com/forum/showthread.php?t=63175


:cheers: vic
 
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