Five Questions about Replacing Air Flow Sensor Are Answered

 

There are many problems about replacing the MAF sensor. Check out the following hot questions to find out when to replace them and the steps to extend their service life.

 

1. How to replace the air flow sensor?

There are many ways to replace the air flow sensor. Here, Jxgertay senior technician shows you how to replace the full-shell air flow sensor at details. Please feel free to contact us at website: en.getaimaf.com.

 

2. When do I need to replace the air flow sensor?

Road debris and other pollutants passing through the air filter will cover the sensing element of the air flow sensor. The coating insulates the components, resulting in insufficient air flow report at idle speed and excessive air report at low speed. The general system is the only exception to excessive air quality reports at low speeds.

 

Usually, technicians first try to clean the sensor. Although cleaning the polluted air flowmeter seems to restore its performance, it rarely makes it 100% operational and accurate. In many cases, the internal circuit will be damaged or short-circuited. In these cases, the sensor needs to be replaced. Because the air flow meter is the key component of the engine refueling strategy, it must be reported with 100% accuracy to ensure peak performance, fuel economy and reduce emissions.

 

3. How does the air flowmeter work?

Modern air flow meters use hot wire or hot film elements. The internal circuit of the sensor heats the element to a specific temperature. When air flows through the element and cools, the sensor will increase the current flowing to the element to maintain the specified temperature.

 

The amount of current required to maintain the temperature of the element is directly related to the quality of air flow through the element.

 

It is important to note that the components of the sensor are only samples of a small part of the airflow. If the intake system is modified or changed due to failure, the components may not receive enough intake air samples, which may lead to measurement errors.

 

If air enters the engine without passing through the sensor (for example, the air pipe between the air inlet and the air mass flow sensor is not installed correctly, or there is a vacuum leak), the real air flow entering the engine cannot be known.

 

4. What is the function of air mass flow sensor?

In the mass air flow system, the calculation of basic fuel is very simple. ECM receives the air mass value from the air mass flow sensor, and then calculates the required fuel injector pulse width to deliver the fuel required by the required air-fuel ratio.

 

Once the requirements for closed-loop operation are met, the ECM will start with the basic fuel calculation and then monitor the oxygen sensor feedback. If the delivered air-fuel ratio is too rich or too lean, the fuel duty ratio of the injector will be adjusted. If the mass air flow sensor of the vehicle underestimates the air flow, the ECM will determine that the mixture is too lean and adjust the fuel adjustment to compensate.

 

Engine load information (for EGR scheduling, shift timing and spark timing, etc.) also comes from MAF sensor. Although the air-fuel ratio of MAF deviation will be compensated by fuel adjustment, the engine load information is not "adjusted".

 

MAF sensor needs laminar flow, which will occur when air flows in parallel layers without interruption between layers. MAF element only samples a small part of the incoming airflow, so if there is no laminar flow, air measurement and fuel delivery will be incorrect. Some older vehicles are equipped with diffusers, but most rely on air filter design to provide laminar flow.

 

"In the past, I replaced the air mass flow sensor and found that it was worse than the one I removed. What should I do?

 

For technicians, nothing is more frustrating than making a diagnosis, replacing parts and finding that it can't cure the disease. If technicians are not confident in their diagnosis, they will usually find another way and replace other parts. For example, every new MAF sensor manufactured by SMP has been calibrated and tested to ensure 100% accuracy, so technicians can rest assured that it can work normally out of the box.

 

5. How to ensure the service life of my new air mass flow sensor?

The first line of defense of the new air mass flow sensor is the air filter. It is very important to install a new high-quality air filter while installing a new MAF.

 

Make sure the air box is well sealed and there are no obstacles in it. If you have attended our professional training seminar, you may remember a case study in which plastic groceries were sucked into the air box and blocked the air filter.

 

 

It is very important to have OE design air filter. Some oiled filters may be over-oiled, which will eventually pollute the MAF sensor and lead to performance degradation. Some cheaper replacement filters have different designs, which will change the direction of air flow and distort the reading of MAF. You may remember the case study of Ford Explorer, in which the air filter changed the air flow and caused deviations in the readings of MAF, barometer and fuel adjustment.

 

Make sure that the air inlet is not equipped with a "performance" airflow device (such as the tornado device you saw in the TV advertisement). These devices can destroy the plane airflow which is essential for accurate MAF reading.