Fuel Injection System: How Does it Know? – UnderhoodService

Fuel Injection System: How Does it Know?

With the days of carburetors behind us, the electronic fuel injection system in the cars we drive today is king. While carburetors mixed the air and fuel together and the mixture was sucked into the cylinder and burned, modern electronically controlled fuel injection injects the right amount of fuel, at the right time for optimum fuel efficiency and economy, and driving performance. But the question remains, how does it know what that 'right amount' is and when's the 'right time' to inject?

With the days of carburetors behind us, the electronic fuel injection system in the cars we drive today is king. While carburetors mixed the air and fuel together and the mixture was sucked into the cylinder and burned, modern electronically controlled fuel injection injects the right amount of fuel, at the right time for optimum fuel efficiency and economy, and driving performance. But the question remains, how does it know what that ‘right amount’ is and when’s the ‘right time’ to inject?

The answer lies in the many sensors located in and around the engine and in the engine’s computer that controls the entire process. The mass air flow (MAF) sensor is at the heart of this system. It includes a piece of very fine wire with an electronic device that measures the amount of air being sucked into the engine and relays that information to the electronic control unit (ECU). Based on this and other information, the ECU decides how much fuel should be injected and when.

“ECUs in modern vehicles are configured to dictate precisely when and how much fuel to inject into the engine for the vehicle to operate at its highest level of efficiency and deliver the best performance of which it is it is capable,” said Chuck Kerrigan, director of marketing for Purolator.

With all the air drawn into the engine passing around the MAF sensor, it must consistently act very quickly and accurately just like all the other sensors in a vehicle’s engine management system. In this scenario, if the vehicle’s engine air filter is torn or otherwise compromised and is not replaced, the MAF sensor is unable to assess the amount of air coming in and, as a result, unable to help the ECU determine how much fuel is needed and when.

Furthermore, because the MAF sensor is hot in normal operating conditions, the dirt that hits it sticks and melts, compromising the sensor’s ‘sensing’ capacity.

The engine air filter, therefore, shoulders a big responsibility. It protects the engine from the dirt and dust that blows around us as we drive, and also supports the MAF sensor in its two important tasks of determining – precisely – the quantity of fuel and timing of injection needed for optimum power, economy, and clean emissions.

“We’ve all heard that an ounce of prevention is worth a pound of cure. Nowhere is it more applicable than in the case of a car’s engine air filter. A relatively inexpensive item, simple to find and replace, a car’s engine air filter is more important in the bigger scheme of the ‘environment’ inside a car’s engine,” Kerrigan said.

Purolator offers two types of engine air filters for passenger cars and light trucks – PureONE and Purolator Classic engine air filters. According to Kerrigan, Purolator’s PureONE engine air filter’s oil-wetted, high-capacity media offers twice the capacity of conventional air filters to trap contaminants smaller than the size of a grain of sand and is 99.5 percent efficient. This means it traps 99.5 percent of particles that size or larger. Likewise, Purolator Classic air filter’s multi-fiber, high-density media traps 96.5 percent of contaminants.

Simply replacing an air filter would cost you approximately $25. On the other hand, with an MAF sensor, which has to be professionally diagnosed and replaced, the cost could jump closer to $400, including parts and labor. While there are chemicals that are commercially available to clean a MAF sensor, the likelihood of success is not high.

So, more rests on a clean engine air filter than you realize.

Purolator is a proud supporter of the Automotive Aftermarket Suppliers Association’s (AASA) Know Your Parts education and awareness campaign. This initiative promotes the importance of quality brand name aftermarket parts backed by full service suppliers to preserve the industry’s good reputation. For more information, visit: www.AASAKnowYourParts.org.

To learn more about Purolator filters and the filtration category, visit www.purolatorautofilters.com.

To learn more about Purolator heavy duty filters, visit www.PurolatorHeavyDuty.com.

To learn more about Purolator Breathe Easy cabin air filters, visit www.BreatheEasycabinfilters.com.

To find Purolator on Facebook, visit: www.facebook.com/Purolator.

To follow Purolator on Twitter, visit: www.twitter.com/Purolator.

 

You May Also Like

Understanding Coolants

All-season coolant used inorganic acid technology and worked great for almost 30 years.

In the 1960s, coolant was changed twice a year. In the fall, antifreeze with ethylene glycol-based coolant was put into the engine to prevent the coolant from freezing and cracking the block when a cold front hit. Often, if the engine got hot, the antifreeze would boil off. In the spring, the engine would be drained and filled with water and maybe a small can of an anti-corrosion treatment.

Ignition System Do’s and Don’ts

Why do ignition systems give technicians problems when diagnosing ignition-related misfires? The answer is that some technicians use tests that might give inconclusive results or do damage to the coil or drivers inside a module.

Tools To Service Serpentine Belts

Servicing the serpentine belt on some vehicles is a tough task.

Battery Charging and Diagnostics

Here are six tips to use when diagnosing a vehicle with a dead battery. 

Why Do Timing Chains Stretch?

As the timing chain wears, it can change the timing of the camshaft and crankshaft.

Other Posts

Carbon Deposits and Direct Injection Engines

The primary cause of these problems is that fuel and added detergents are not hitting the back of the intake valves.

Acura Turbo Engine Service

It is important to check the operation of the solenoids that control vacuum to the actuators.

Subaru EJ25 Head Gasket Problems

Most of the EJ head gasket failures occur around the 100,000-mile mark and start as a slow oil or coolant leak.

New Oil Specifications

Many 0W16 oils have a new donut certification mark on the bottle called API SN-PLUS and SN-PLUS Resource Conserving.