Any vapour feed system experts?

[eurasiaoverland]

'96 3RZ-FE Hilux Surf (JDM 4Runner)

I have a Japanese Hilux Surf with the 3RZ. The vapour system is slightly simpler compared to US market 4Runners (just one solenoid valve and far fewer vacuum lines - and no EGR from factory) but presumably works on the same principle.

At idle, I can hear the VSV on the charcoal canister clicking repeatedly. This stops when the engine is revved. Is this normal?

I've noticed that the short hose going from the canister to the valve is hardened and cracked at each end, and may not be sealing properly (I am about to order a new one), but the longer vacuum hose from the throttle body to the valve looks fine.

Can anyone confirm if the clicking is normal, or likely to be related to a poorly fitting hose?

I assume the valve is there to stop the fuel vapour coming out into the inlet system, and then venting to atmosphere, when the engine is not running?

What's the drain for in the bottom of the charcoal canister? To drain fuel out in case of the charcoal canister being flooded?

Thanks

EO

 

[19963.4lsr5]

Only way I’d be able to tell how often my valve cycles would be to put a light on it. I can’t here it otherwise.

Do you have a hose going from the canister to the air box? For when the engine is pulling air through the canister?


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[eurasiaoverland]

Only way I’d be able to tell how often my valve cycles would be to put a light on it. I can’t here it otherwise.

Do you have a hose going from the canister to the air box? For when the engine is pulling air through the canister?


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You can get a mechanic's stethoscope for almost nothing from eBay which opens a whole world of noises from your engine, and anywhere else you stick it.

 

[phattyduck]

At idle, I can hear the VSV on the charcoal canister clicking repeatedly. This stops when the engine is revved. Is this normal?

Can anyone confirm if the clicking is normal, or likely to be related to a poorly fitting hose?

I assume the valve is there to stop the fuel vapour coming out into the inlet system, and then venting to atmosphere, when the engine is not running?

What's the drain for in the bottom of the charcoal canister? To drain fuel out in case of the charcoal canister being flooded?

Thanks

EO

The clicking is likely normal. I have a JDM '95 Celica GT4 drivetrain in my Camry, and that's how it runs the vapor canister solenoid. I found out because I installed the solenoid inside the vehicle (connected to nothing) and was quickly annoyed by the clicking.

And you are right about the function - it is there to stop vapors from escaping except when the ECU wants to feed them to the engine. The clicking is probably a slow pulse-width modulation to limit the amount of vapors that go to the engine.

-Charlie

 

[19963.4lsr5]

You can get a mechanic's stethoscope for almost nothing from eBay which opens a whole world of noises from your engine, and anywhere else you stick it.

Yea, I got one of those.


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