General System Description

Fuel System-Compressed Natural Gas (CNG)

The Fuel System Components






WARNING:

- Do not modify the system configuration or components, or replace components with parts not specially designed for use with natural gas. Ford Motor Company Ltd has specially designed the materials, components, and system configuration for the 2.0L Contour CNG vehicles, and each particular system is precisely calibrated for efficient operation. The use of different parts or materials can produce an untested configuration that could result in fire, or cause engine damage. Failure to follow these instructions may result in personal injury.

The compressed natural gas system consists of, a gas regulator, a combined metering valve and computer (compuvalve), a gas supply manifold, a selector switch to facilitate communication, and an alternative fuels control module (AFCM) to exchange data with the powertrain control module (PCM). Incorporated into the compuvalve are absolute pressure sensors (fuel and intake manifold) and a fuel temperature sensor. The system operation may be summarized as follows:

- Fuel from the natural gas fuel tank flows through a coalescer filter to the high-pressure regulator.
- The regulator provides a consistent operating fuel pressure 690 kPa (100 psi) for the system.
- The fuel is passed to the compuvalve, which electronically meters fuel according to demand, and controls spark advance for optimum power. The inputs from the PCM are used to dynamically monitor the engine and environment to provide closed loop control of fueling.
- The fuel is then introduced into the air intake manifold through the fuel supply lines.