Evaporative emission control question...

J

JFLLincoln

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Hi all, still chasing a fuel odor issue that threatens to ban my 2800 CS (VIN 2270521, US spec. originally sold in CA) from our attached garage... banishment is tantamount to having to sell as I won't allow the car to sit outside...

Thus far I've replaced all soft fuel lines, the large diameter rubber connector from inlet pipe to fuel tank, electric (aftermarket) fuel pump, sender unit o-ring and have subjected the fuel tank to the "Renu" process. Prior to refilling the fuel tank I'm going through the evaporative fuel control system... and the emission control sticker under the hood is completely illegible...

I traced the entire evap. control system and it consists of:

- Hard plastic line (& braided/rubber tubing connectors) from fuel tank to vapor expansion tank

- Expansion tank

- Hard plastic line (& braided/rubber tubing connectors) from expansion tank, through passenger compartment and thru the firewall.

- Braided rubber tubing from firewall to a connector on the stock air filter housing

- Fuel tank cap is unvented

I've seen references to (and diagrams showing) a charcoal canister, but I haven't found one... knowledgeable sources have indicated it should be under the battery tray and that the vapor emission line should go from expansion tank all the way forward to the charcoal canister (under battery tray) and then from there to the air filter housing. Questions follow:

- I'm the second owner of the car and I don't believe the original owner modified the vehicle in any way... does the above evap. control scheme on my car (no charcoal canister) match anyone else's experience?

- Thoughts appreciated on the following alternatives I'm considering:
- Keep plumbing as is, just replace all lines to air filter housing
- Same as above but add some kind of check valve to reduce fugitive vapor emissions
- Add a charcoal canister to the above system prior to air filter housing connection
- Add a charcoal canister in the trunk (downstream of expansion tank) and vent the canister to underside of car, abandon all tubing going forward to air filter housing

Sorry for the long post... any suggestions/input appreciated!

Jim
 
Early cars did not have the charcoal can, our 4/70 2800 sedan does not have one either. The line attaches under the air filter as you stated. Be sure the rubber hoses are all replaced. The one from the firewall to air cleaner is funny, large (6mm) at firewall, maybe 4mm at air cleaner, depends where connected perhaps. I don't think the can will make a difference. Just needs good suction to pull fuel vapors from trunk bottle to engine, that solved fuel smells in my coupe years ago.
 
I vent the fuel tank through a hose from the filler neck down and out through a hole in the trunk, eliminating all forward connections. No smell.
 
Gasoline emissions from car leads to gasoline smell in the house... the wife doesn't like that... this is not a regulatory thing...
 
Unless it goes through the carbon canister it won't cure the smell.

When I first had the coupe back in '88 I had the smell too, found something wrong in the hoses or a crack in the expansion tank. Long time ago, I think it was one of the fuel hoses IIRC.

My Europa doesn't have the evaporative system since I converted it to Webber head Dellortos, the float bowls keep fuel in them for a few months w/o evaporting; not smelling up the house.

Maybe you should vent the garage!
 
Have you isolated the smell to either coming from the trunk or the engine bay?

If the engine bay, you could try capping the vent at the filler neck. If the smell is still coming from the engine bay, then perhaps it could be the carbs. My Zeniths were always a bit stinky, especially right after pulling into the garage. One of the reasons I went to EFI.

good luck
 
Thanks to all for the suggestions... I've tried sealing the garage from the upstairs... have considered getting more air circulation thru the garage and may do that.

With regard to source of the odor, the only thing I'm sure of is that the venting of the float bowls alone is not enough to cause the problem... I drained the tank and removed it for rebuild, left the coupe in the garage and there was no problem. Will try replacing all the plumbing in the evaporative control system, if still a problem will add the charcoal canister.

Thanks!

Jim:roll:
 
Jim, I would try Steve's suggestion because it eliminates doing anything to the evap system, costs nothing and will allow you to determine if the fuel smell is from the front or the rear of the car. I think you mentioned that you did replace the sender unit o-ring which is a major source of stink from my experience.
 
A rose by any other name...

My 7/1970 2800CS doesn't have a charcoal canister either. The smell is definitely in the trunk, but that could be in part due to a cracked expansion tank. I'm planning on putting in a charcoal canister with some solenoids that will open when the car is running and allow the gas vapors to flow to the air cleaner.
I'll run new hoses from the back, and I have purchased an E3 expansion tank as a replacement. I know my carbs don't hold fuel very well since I have to crank the engine a fair amount to start if the car has been sitting several weeks. When it is in the garage, I can't tell if there is additional smell coming from the front. I'm building a carport, so the car will be protected, though not usually in the garage..

Ian
 
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