Evaporative Emission System High Purge Flow

Possible causes

• CommonFailed purge control valve
• CommonCorroded connector or damaged wiring
• CommonSplit, perished or disconnected purge hose
• CommonValve stuck open by debris from a degraded charcoal canister
• PossibleBlown fuse on the circuit
• RareFailed control module driver

What you might notice

• Hard starting immediately after refuelling
• Rough idle
• Stalling shortly after starting
• Fuel smell
• Failed emissions test
• Check engine light on

What to check, in order

1. Check whether the car is hard to start straight after refuelling, and easier to start if you hold a little throttle. That combination points firmly at a purge valve stuck open.
2. Check the valve holds vacuum with no power applied. A valve that passes air when closed is the fault.
3. Inspect the charcoal canister. A canister breaking up sends debris into the valve and holds it open, and fitting a new valve without replacing the canister repeats the failure.
4. Note whether the car is hard to start straight after refuelling. That symptom is close to diagnostic for a purge valve stuck open, and it costs nothing to observe.
5. Check the purge hoses for splits and disconnection.
6. Measure the valve winding resistance against specification.
7. Inspect the connector for corrosion.
8. Check whether the valve holds vacuum when closed. A valve that leaks with no power applied is stuck open, and that is what causes the hard starting.