strange event

[siii8873]

I've had two SIII's and this system was gone on both of them. My first one had the hoses running behind the seat box and a canister in the wheel well behind the drivers seat and a bracket in the engine compartment where another canister was located. The supply to this system was blanked off. There are no remnants of this system on this truck just the blanking plate on the tank.
These systems were a evap system, which I have seen in the green bible but never in service on a truck. The parts are NLA and usually just blanked off (RN sells the blanking plates for this).

[bkreutz]

I must have a rarity then, all the vent stuff is there. If you have a blanking plate, you could take it off, drill a hole and tap it for a barbed fitting, then run a vent hose somewhere (higher than the filler neck) and put a foam filter on the end of it. Or you could get fancy and put a valve that allows air in but doesn't allow fumes to vent out, but with my luck the first thing that would happen is the valve would get stuck closed. Or you could just leave the cap vented, They were all that way until the EPA got involved. (I'm not recommending this, just in case the "vapor police" are reading this.)

[siii8873]

My only concern with the hole in the cap is getting moisture in the tank over time.

[SafeAirOne]

My only concern with the hole in the cap is getting moisture in the tank over time.

Forgive me if I misunderstand the above statement, but it prompts this response:


I believe that any fuel tank that vents to the outside air poses that risk.

Note that ALL fuel tanks are somehow vented to the outside air (or else they'd all develop vacuums as the fuel is being used, as you know).

I can't think of one that uses a desiccant or other type of air dryer, so I doubt your in any more moisture danger than all the other vehicles on the road by venting your gas cap.

The non vented gas caps still had vented fuel tanks--They were just vented through a charcoal canister.

[cousindave]

Siii8873: just drilled my cap after reading this post. My rig runs much much better. I also had replaced my fuel cap with a new one that sealed too well!

[siii8873]

Cousindave,
that's great that this post helped you. That's a great thing about this forum.
Bob