evaporative emmission canister 1999 superduty

I noticed a strong gas odor while driving my 1999 Superduty V-10, which I recently acquired. I checked for fuel line leaks and then looked into the charcoal evap. emm. canister. This canister has one hose going to it from the gas tank to collect vapor and then it just has an open vent on the front end which vents into the engine compartment. I think this is the source of my gas fumes. I've check out two different shop manuals and they describe a purge valve system which removes vapor from this canister and routes it to the engine for burning. My truck was built in Canada, and it either never had this purge system, or it has been removed. I can't find any clear photos showing this setup. Does anyone have any info on this? I need another way to route the gas vapors other than into the engine compartment - I got quite a buzz driving in hot weather the other day with the AC on - the AC picked up the fumes and dumped them into the cab!

Thanks

John

Reply to
Doctor John
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Until you get it fixed, run the AC on Max. That should recirculate cab air only.

Spdloader

Reply to
Spdloader

Thanks - that's a good idea. I've been looking around the engine compartment and the canister purge system appears to be non-existent ... it isn't just disconnected hoses. I'm thinking of drilling a 1/4 inch hole in the air filter casing and using vacuum line to vent the canister directly into the air intake ....

Reply to
Doctor John

I'm not going to say don't do it, but I wouldn't, there's no way to control it, because the computer can't gauge it. You'll have another issue if you do that. Is the smell worse when your tank is full? Hot weather can make lots of fuel vapor. Could be the canister element is saturated. Could be it's not the culprit at all.

Spdloader

Reply to
Spdloader

The tank was about 3/4 full and it was about 85 degrees outside. This was the first time I ran the AC on this truck. I'm fairly certain the fumes were coming from the canister - it just vents into the engine compartment. From what I can read by the shop manual, the purge valve system may be optional, so maybe it was never installed in this truck. What is missing is the canister vent solenoid and the evap emissions canister purge valve plus all the electronics and hoses. I took out the canister and blew air through it and now I'm letting it dry out in the sun. I will probably replace it, but I wonder how long until a new one gets saturated? It seems weird that it would just vent into the engine compartment. Maybe there is a cover on the large (about one inch) opening which would normally have a purge valve attached - I wonder if I should plug this up? I agree venting into the air cleaner is risky, so I'll probably scratch this idea. Thanks for the input - I'm open to any other ideas on this.

John

Reply to
Doctor John

That piece should last the life of the truck. It is full of little charcoal granules. The charcoal 'holds' the fumes. The mass of granules is held under pressure by a spring-loaded flap under the top of the cannister.

It doesn't made sense that the piece is there and a line is going to the fuel tank, but the purge system is missing. It had to have been removed. Just the purge system being 'optional' doesn't make sense either. I'd either head to a Ford dealer for some help, or find a similar truck and check out it's system. Car lots, junk yards, Ford truck clubs would be good sources for info. Try asking your question here:

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That group should be able to help.

Dave S(Texas)

Reply to
putt

The shop manual CD I have shows both of the missing parts and states " if equipped" which I think means these are optional. I blew some air at low pressure through the canister and it just flows through - no backup pressure. I agree it doesn't make sense for it to vent into the engine compartment. I'll check out the site you recommended. Thanks

Reply to
Doctor John

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