Neon L4-2.0L VIN C (1997)
Rollover Valve: Description and Operation
All models pass a full 360 degree rollover test without fuel leakage. To accomplish this, fuel and vapor flow controls are required for all fuel tank
connections.
All Neon vehicles have two rollover valves. One in the fuel filler tube and the other on the top of the fuel tank. The valves prevent fuel flow
through the fuel tank vent valve hoses should the vehicle rollover.
An evaporation control system is connected to the rollover valve(s) to reduce emissions of fuel vapors into the atmosphere. When fuel evaporates
from the fuel tank, vapors pass through vent hoses or tubes to a charcoal canister where they are temporarily held. When the engine is running, the
vapors are drawn into the intake manifold. Certain models are also equipped with a self-diagnosing system using a Leak Detection Pump (LDP).
Refer to Emission Control Systems for additional information.
