Engine Electrical: Design: Injectors

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Injector

Courtesy of VOLVO CARS OF NORTH AMERICA.

The function of the injectors is to spray fuel into the cylinders in the correct spray patterns. This happens sequentially.

The injectors are in the intake manifold.

It is essential that the injectors are correctly installed with no air leakage around them. Fuel leakage from the top of an injector when it is not activated may lead to starting and driving problems.

The engine control module (ECM) controls the injectors using a pulse width modulation (PWM) signal.

The engine control module (ECM) can diagnose the injectors. The injectors can be activated using VIDA.

Air-shrouded injectors

Cars from model year 1999-2000 have air-shrouded injectors.

The injectors are in the air distribution pipe which is in the intake manifold.

The lower section of the injectors has 2 openings in the side where air can enter.

When the needle in the injector starts to rise, the openings are exposed. This allows air to flow in to the center of the valve at high speed, and the fuel and air are finely distributed and mixed.

When the needle rises further, the injector nozzle opens and the air/fuel mixture is released into the combustion chamber.