• From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Topic: What is the proper way to remove the EVAP system?

For some screwy reason Jaguar put the EVAP canister behind the right headlight socket, blocking the flow of air to our brakes. I removed the whole assembly, but I've never yanked a charcoal canister off a driveable car. What do I need to do with the gas tank line? I'd leave it as is, but I don't want to take a long sweeping turn and start siphoning my tank onto the track. I've read some forums where people talk about putting a breather on it, but that sounds like putting a band-aid on a sucking chest wound. If I run the line straight to vacuum on my intake, it might siphon the tank directly into the manifold, right? If I plug it I might build pressure in my gas tank. Do I need to build a catch can with a breather on top? Or should I just plug it?

  • sergio
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Re: What is the proper way to remove the EVAP system?

The EVAP line is the tank vent, so you can't plug it. There should be a solenoid near the canister or engine on the line. It's controled by the engine computer. My guess is you can bypass the canister without problems. The canister absorbs gas vapors when the car is sitting, then they are sucked into the motor when you're driving. I'm not sure if the line on the motor has vacuum all the time. It might just have it at part throttle, kinda like ported vacuum on old carburated cars.

  • bob-e
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  • From: Middle, TN
  • Registered: 2009-06-08
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Re: What is the proper way to remove the EVAP system?

Just unplug it unless you already have gas pouring into your charcoal canister.  Then you have bigger problems

  • From: Seattle, WA
  • Registered: 2009-10-28
  • Posts: 2,111

Re: What is the proper way to remove the EVAP system?

I've (ahem) heard of people in similar situations removing the canister, plugging the line or removing it and plugging the tank, then substituting a vented fuel cap-- check if there's one that fits.  Also, "for some screwy reason Jaguar..." is a line of thinking that only leads to frustration; better to embrace the fact that there's no reason whatsoever for anything found on any British car.

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  • From: WOOTville USA
  • Registered: 2009-05-06
  • Posts: 2,415

Re: What is the proper way to remove the EVAP system?

^^+1^^

I left our charcoal canister on as a catch can/breather (and for smog checks, HA!). Plugging it and running a vented cap like Mike says will work. 

The smallest drill bit you can find helps makes a good vented cap.

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  • From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Re: What is the proper way to remove the EVAP system?

Also, "for some screwy reason Jaguar..." is a line of thinking that only leads to frustration; better to embrace the fact that there's no reason whatsoever for anything found on any British car.

My point was that they could have left the charcoal canister and headlight off and the airflow would have been perfect.

We are still trying to figure out how they fit so much unnecessary crap into such a large car. The interior is filled with unbolted parts, the trunk's filled with parts, my Caddy's trunk is full of parts, and it's not like the Jag's interior and trunk are small!

As far as my original question, the gas tanks (yes, plural) have hinged caps on top. and I can check later to see how well they seal. I'll probably end up capping off the EVAP line.

  • From: Corona, CA.
  • Registered: 2009-08-03
  • Posts: 359

Re: What is the proper way to remove the EVAP system?

The best strategy is probably to put a small filter on the line which formerly connected the canister to the gas tank.  Why?  If your Jag is reasonably modern, it has a roll-over valve on the gas tank where the EVAP line(s) connect.  If the car were to roll over, the rollover valve should seal and you should not have any gas leakage from that vent line.  If instead you plug the vent line and install (or make) a vented gas cap, gas will leak from the cap in the event of a rollover.  Something to think about...

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  • From: Long Beach
  • Registered: 2009-04-30
  • Posts: 232

Re: What is the proper way to remove the EVAP system?

Put the canister somewhere else and hook the vacuum lines back up. Why fuck with the fuel system? To save 2 lbs on a Jag?

  • From: Lost in the Rockies
  • Registered: 2009-10-06
  • Posts: 1,008

Re: What is the proper way to remove the EVAP system?

Eyesoreracing wrote:

Put the canister somewhere else and hook the vacuum lines back up. Why fuck with the fuel system? To save 2 lbs on a Jag?

I don't think the issue is the 32 ounces of road-hugging weight but its location: right where they want to run a brake-cooling duct.

I like the idea of an inline filter to replace the canister.

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  • From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Re: What is the proper way to remove the EVAP system?

I didn't think of an inline filter. I have one on my parts shelf that I got free with a fuel pump. Thanks!

11 Reply by djcommie (edited by djcommie 2009-12-15 08:14 PM)

  • From: Santa Margarita, CA
  • Registered: 2009-06-03
  • Posts: 177

Re: What is the proper way to remove the EVAP system?

As said before, using a vented filler cap and blocking the tank vent and purge to manifold lines will make sure that you won't dump (as much) fuel into the engine bay if you rollover.

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  • From: Corona, CA.
  • Registered: 2009-08-03
  • Posts: 359

Re: What is the proper way to remove the EVAP system?

djcommie wrote:

As said before, using a vented filler cap and blocking the tank vent and purge to manifold lines will make sure that you won't dump (as much) fuel into the engine bay if you rollover.

If that's the case, then why don't stock, unmodified cars leak gas into the engine compartment if you roll them over?  I bet that NHTSA has a safety standard for that, and it's not allowed to leak ANY gas in a rollover.  The stock EVAP system has rollover valve(s) to prevent fuel leakage if it's rolled over.  How will a vented filler cap NOT leak if the car is upside down?

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  • From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Re: What is the proper way to remove the EVAP system?

Typically a vented cap has a paper filter in the vent that allows air to breathe, but slows fuel flow down to a trickle in the event of a roll over. Take a look at your lawnmower's gas cap.

14 Reply by djcommie (edited by djcommie 2009-12-18 10:11 AM)

  • From: Santa Margarita, CA
  • Registered: 2009-06-03
  • Posts: 177

Re: What is the proper way to remove the EVAP system?

EriktheAwful wrote:

Typically a vented cap has a paper filter in the vent that allows air to breathe, but slows fuel flow down to a trickle in the event of a roll over. Take a look at your lawnmower's gas cap.

Maybe I should have clarified that Vented caps do meet that requirement, the newer ones are "vented' as some let air in, but not much out. I'm not talking 60s Chevy ones with external prongs and a cork gasket.

Evap systems really should be plugged at the tank, modern cars tend to have a plastic line which is quite good but can be cracked or damaged. I know of more one NB Miata with a bad canister/line from tossing a rock through it/them.

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  • From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Re: What is the proper way to remove the EVAP system?

The Jag has a steel line, but it doesn't have a normal gas filler cap. It has two 7.5 gallon tanks that each have a shiny chrome cap on top.

  • sergio
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Re: What is the proper way to remove the EVAP system?

EriktheAwful wrote:

The Jag has a steel line, but it doesn't have a normal gas filler cap. It has two 7.5 gallon tanks that each have a shiny chrome cap on top.

Those gas caps are a carry over from Jaguar's early racing days. They snap shut.

  • From: Choctaw, Oklahoma
  • Registered: 2009-11-12
  • Posts: 2,144

Re: What is the proper way to remove the EVAP system?

...and I don't think they really seal all that well. I may just cap the line and call it good, but it'll have to wait until tomorrow before I can check it out. I've been averaging 6 day work weeks and the rest of the team is just as busy.