As in other cases – customers’ data are known; this is not a company’s defamation. True thought, the data are painted to reduce the possibility that the company tries to take revenge on customers for data leakage.
Without a long introduction, I will publish the data of the injector diagnostics, and then the description will follow – what has gone wrong now.
As we see, two injectors are defectives. True though, data regarding the 2nd injector have “gone astray”, but everything is fine; they are available regarding others.
It’s time for remark: complaints of the customer – vibration, misfires, unburned fuel during cold start. The situation becomes correct when the engine at least partially warms up.
Accordingly – we could hope to see some leakages/spillings in closed conditions or the leaking of the injector – an increased amount of injected fuel.
Let’s see what the test data shows to us.
R2LC electrical test. Data of all injectors: 2.6 (uF). I doubt that this measurement really has been performed because – of identical measurements for all 6 injectors? Unlikely. Second remark: inadequate range of allowed values (1.5 .. 4.5) means that even China’s “analogs” and other “miracles” will pass this test. Unfortunately, the injectors with inadequate electrical capacity will not work normally!
NLT leakage test. Here we got our first disappointment. In reality, injectors are leaking. Unfortunately, none of the injectors leaks during the test due to room temperature! I haven’t seen ANY injector from all test results gathered over several years, which would fail this test at room temperature! Yes, exactly – the injectors start to leak in the cold but do not leak in room (and higher) temperature. In reality, the test, which is intended to identify leaking of the injectors (and leaking is the most popular defect of these injectors), turns out useless!
TP4 flowrate test for short openings. This is the second most crucial test (after NLT), which could identify problems with the leaking of the injectors and increased amount of injected (or even flooded) fuel. Yes, the 3rd injectors haven’t passed this test! But the amount injected by this injector was REDUCED!
Now, let’s see the parameters describing the Delay of these injectors; they are 194 and 212. Lowest in this “company” of the injectors. Encoding data of these injectors indicates that these are the “least productive” injectors for short opening mode. Diagnostics confirm it. In my evaluation – the test has passed successfully, even more – the injectors “behave” very correctly, according to their encoding! Test results correlate (are proportional and comparable) with other “healthy” injectors.
Why did it happen as it did? There are several reasons, and they are well known:
a. incorrect min/max values (inappropriate for these injectors);
b. ignoring the encoding data, creating min/max values of the exact injector;
c. min/max values are fixed, not adaptive for the injectors group – does not take into account any differences from the standards due to pressure sensor, air temperature, pressure, humidity, and other obstacles.
The remaining parameters, which do not correspond to the min/max corridor, are only 2 .. 4% below the min value. And again – the injector is not leaking/not closing, but – its flowrate is slightly below the norm.
Let’s put the data of the injectors in the Excel table:
What does this data tell me?
First – in my evaluation: no problems with the injectors. In the column “delta”, the scattering of the parameters of the injectors is calculated. It is less than the one allowed by the manufacturer (included in the encoding data). In addition, we have to understand that the scattering of the used injectors can be (and usually is) even wider than for new injectors. And that is normal!
For example, scattering 0.19 for the TP3 test means that the scattering of the injector parameters is 19% or around +/-9.5% against the average value. This is an excellent result!
As expected, the most considerable scattering of the parameters is for short openings: 39%, but this result is also acceptable (narrower dispersion as Coding data says; much more limited distribution, which allows compensating adaptations)!
Remember that Carbon Zapp doesn’t take into account the encoding of the injectors!
One more nuance which has to be kept in mind – min/max value corridors will work correctly in case the pressure sensor of the test equipment, verified scales; test fluid, temperature, air pressure, humidity etc., corresponds to the intended measuring conditions. In reality – unfortunately, these conditions are far from the exact/initial, and conclusions, which are drawn from the “automatic” report – are incorrect.
Summary
In this test, two injectors are marked as defective unreasonably, but the true problems (as usually/in all other tests) are not detected. Yes, it is possible that one of the injectors, marked as defective, also leaks in the cold (coincidence), but as part of this test – there is no reason to mark them as faulty!
And finally – these tests do not evaluate the atomization of the fuel or beam angle/shape. Both parameters are MEGA important for the DI engines, but for these (N43/N53), which work in Stratified charge – even most essential parameters for this injection mode. Unfortunately, this injector test is of shallow value without a precise evaluation of these parameters.
All necessary data for these engines are given by INPA live data, which are saved in the exact conditions. INPA allows for evaluating the leaking of the injectors, atomization quality, and actual flowrate values in different modes. INPA gives information regarding the proper conditions, not some tests in room temperature.
