Evaporative Emissions System: Operation

1982 Volkswagen Rabbit Base, 2D HatchbackSECTION Operation

Fuel vapors pass through the carbon canister and deposit hydrocarbons on the surface of the carbon. When the engine is running, fresh air entering the canister through an opening cleans the carbon and routes the hydrocarbons via the air cleaner back to the engine for combustion. On all fuel injected models, a fuel return line is used to prevent excessive pressure build-up at idle speeds.

Fig 1: Quantum Carbon Canister-to-Intake Manifold Flow
G09315576Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.