Evaporative Charcoal Cannister - Electronic Solenoid

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rSpider
Posts: 2
Joined: Mon Sep 05, 2011 3:51 am
ECU Model: S60 Pro
Location: London

Evaporative Charcoal Cannister - Electronic Solenoid

Post by rSpider »

I have an S60 DTA ecu on a 2.0 Renault Spider. The engine is boosted with a Rotrex supercharger currently at around 8 psi of boost. I'm not sure whether I need to do anything about the Vacuum hose that runs from the Inlet Manifold to the Electronic Solenoid connected to the Evaporative Charcoal Cannister. This solenoid was controlled by the original ecu to open/close the vacuum hose that vented the charcoal cannister into the inlet manifold under vacuum in certain conditions. e.g. to burn the fuel vapour in hot weather instead of causing a petrol smell around the car.

This electronic solenoied is no longer wired in since using the DTA ecu. I am worried that this vacuum pipe is now under boost. Am I loosing boost into the Charcoal Canister and/or fuel tank or is it likely the solenoid is shut by default if it's not wired in? Also if it is shut by default is pressure building up in the cannister and fuel tank if it's not being vented?

I was thinking about removing the vacuum hose and solenoid and venting the canister directly to atmosphere. Would that be the best solution?

Any advise would be much appreciated.
VR6Turbo
Posts: 329
Joined: Wed Mar 17, 2010 9:24 am
ECU Model: S80 Pro
Firmware Version: 62

Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by VR6Turbo »

Put a non-return valve in the vac line (the kind you see in brake servo hoses), or just delete the carbon canister system altogether and vent the hose to atmosphere.

The purpose of the carbon can was more to do with EU3 (IIRC) emissions where the engine had to ingest all of it's waste gases by law, including petrol tank vapours. Prior to that, cars just had a little atmosphere vent near the petrol filler flap.

If you route the hose low under the car, the airflow will draw the fumes away, but you may get the odd whiff of it sat in traffic.
rSpider
Posts: 2
Joined: Mon Sep 05, 2011 3:51 am
ECU Model: S60 Pro
Location: London

Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by rSpider »

The non-return valve sounds like a good idea. When pressure builds up in the fuel tank then it would force the valve open and vent into the manifold most likely when at low boost on idle.

I'm guessing I should remove the electronic solenoid that currently operates the vacuum pipe to make sure the system is open and will vent as required.

Damn. I've probably been running boost into the cannister and maybe the fuel tank and pressurising it.... If so then the fuel pressure regulator has probably been running overtime to maintain constant pressure.
stevieturbo
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Location: Norn Iron

Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by stevieturbo »

A non return valve would allow intake vacuum to suck on the tank. I would not do that.

Although if the solenoid is left in place with no ecu control, it will simply be shut.

Just vent it to atmos and dump the solenoid.
Roverdose
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Joined: Tue Aug 09, 2011 2:54 pm
ECU Model: S80 Pro
Distributor: Roverdose
Location: Stevenage
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Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by Roverdose »

id remove and blank it off. if it used to be power open on vacuum it may well only be a soft spring holding it closed (as it would never have seen boost).

Drew
Jon K
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Joined: Fri Dec 04, 2009 1:45 am
ECU Model: S80 Pro
Distributor: DTA UK
Firmware Version: 73
Location: Pennsylvania, USA
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Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by Jon K »

Would be cool for DTA to periodically ground an AUX for proper evap control
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welshpug
Posts: 130
Joined: Tue Sep 06, 2011 4:53 am
ECU Model: S40 Pro

Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by welshpug »

I dont think the solenoid valves are open with no power, so you wont have been feeding boost into the fuel tank, you would have potentially experienced strange fuel pressure behaviour if you were!
Roverdose
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Re: Evaporative Charcoal Cannister - Electronic Solenoid

Post by Roverdose »

ahh i didnt say open with no power, i said power open on vacuum with a spring holding it closed at all other times. wouldnt need to be a strong spring as a nasp engine never sees positive pressure.

Drew
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