Standalone engine managements, such as Pectel, used in this case, do not use mass air flow sensor to figure out how much fuel needs to be injected to maintain desired air/fuel ratio. Instead of such, they equip Manifold Absolute Pressure sensor (hereinafter referred as MAP sensor), which measures only the present pressure in the intake plenum.

Because density of the air is highly dependant on the temperature, it needs to be measured. This is done with Intake Air Temperature sensor (hereinafter referred as IAT).

As we well know, PV=nRT. (pressure x volume = amount of substance x constant x temperature). If either of the sensor signals, MAP or IAT gets corrupted or interfered, the calculation for determing the "n" in the equation goes desperately wrong, causing the air/fuel mix to go amiss.

In the pictures You can see, the water injection nozzles point almost directly towards the IAT sensor.

Water is used to cool down the intake air, and the combustion chamber, for safer operation of a high performance motor.

In all circumstances, the water, that's being injected, is significantly colder than the air, that's entering the motor. This is due to the heat raise caused by the turbocharger, despite of the fact of using the intercoooler. Intercooler efficiency is never full 100%, but more likely around 60-80%. In these circumstances the normal intake air temperature,
on high load, in these motors is around 50-60 celsius.

When cold spray of water is directed to the sensor, the signal it gives of the temperature of the intake air, gets distorted.

This is a fundamental mistake in the setup. This flaw causes improper mixture in the combustion chamber, and therefore using the water injection, set up like in the photos attached, may cause severe damage to the motor.