Determine camshaft and crackshaft position and sends this information to the ECU. The computer uses this and other inputs to calculate injector on time and ignition system timing.

What they do

Sense and signal the ECU, changes in atmostpheric pressure and / or engine vacuum so the computer can control the fuel and ignition operation for varying

What they do

Measure the fuel temperature at the rail thus determining the density of the fuel.

What they do

Measure engine coolant temperature and signals the ECU to adjust the fuel mixture.

What do they do?

Measure air temperature in the intake manifold. The sensor's resistance changes as the temperature increases or decreases. The ECU receives this change in signal and adjusts the injector pulse width and fuel mixture accordingly.

Fuel Pumps

What they do

All vehicles with engine management systems utilise an electric fuel pump, its purpose is to deliver fuel from the fuel tank to the engine/engine management system at the required pressure and delivery rate. The pressure and delivery rate vary according to the vehicle to which it is fitted.

Later vehicles are often fitted with a fuel pump module/assembly  which includes the fuel level gauge sender unit. It is also becoming more common place to incorporate the fuel pressure regulator into the same unit.

Catalytic Convertors

What they do

Catalytic converter is a post-engine “filter” that uses a combination of heat and precious metals to chemically convert an engine’s harmful emissions into less environmentally damaging ones.

Front Pipes

What they do

They connect the engine or manifold to the catalytic converter.

In light of recent news stories, here at APSW we thought we'd write a topical article on the 'ol oxygen sensor (by the way, we have loads of in stock), more commonly known as the lambda sensor.

What they do?

A lambda sensor is an oxygen sensor that fits into the exhaust system. Its purpose is to send a voltage signal to the ECU relevant to the oxygen content of the exhaust gasses. The ECU uses this information to continually adjust the engine’s fuelling requirements.

Engine Management

What it does

Engine management is the electronic control of an engine’s ignition and fuel systems. Many components are required to facilitate this.

Diesel Components

The majority of new cars supplied into the UK are now fitted with a diesel engine. Virtually every light diesel vehicle made since 1997 has been fitted with an electronic diesel system.

Ignition Coil Packs

What do they do?

A high voltage transformer that converts the vehicles 12 volt battery supply to the 25-30,000 volts needed to jump the spark plug gap. Triggered by the engine management ECU.