I am swapping out my fuel pump for the 3rd time. It has been 9 years since I did it last. 1 problem was the line going from the tank to the evap canister is super loose. It has barely any friction holding it to the rubber connector at the canister. The tank side is fine. The canister side of the rubber couple has a spring clamp that looks cracked but is still holding good. The tube side has no clamp and looks like it never did but is loose. I put a hose clamp on it so that should be good. The purge tube is on good an seems OK. Now to the real question. What I think is the air tube (fresh air inlet) just goes to a spot buy the upper driver side of the tank with nothing connected to it. Is that right? I do not remember it from the last 2 times I did this job. I searched on this and other sites but found nothing. The plastic line does not have a clean 1/2 inch like something used to be there. Shouldn't it have a filter or screen on it or go somewhere? There is no other line that is unconnected for it to go to.
Looking at http://shbox.com/1/evap_system.jpg
it is the tube going to number 2 in the Fuel Vapor Canister image

 

“2” is a vent that allows air to enter the canister when the system is purging, and exit to atmosphere when the tank pressure is venting, and the carbon in the canister has adsorbed the hydrocarbons.

As shown in the diagrams nothing is connected, and as I recall from many years ago, there was nothing connected there on my 94. On the other hand, my tank had been removed twice by a shop, prior to my deleting the canister. A hose toward the side of the tank sounds reasonable. Seems that if a filter or screen was required, it would have been shown in the factory service manual. And that’s where Rob/Shoebox found the diagrams.

 

I would at least expect a screen to keep spiders, mud wasps, etc out of the tube. I also don't remember noticing and worrying about it the last 2 times. Maybe I only noticed because of the problem with the other tube. I was able to see that most evap systems have a separate solenoid to activate the vent but I do not see one on the car or at shbox.. Maybe not used on OBD1?

 

The only thing they changed on the 96/97 OBD-2 LT1's was the addition of a vacuum switch to help detect problems with EVAP purge system flow during "no flow commanded", and no flow during "flow commanded". All the other components appear to be the same, at least from looking at the factory service manual.

The "EVAP canister vent valve" was added with the 1998 models, both the LS1 and the V6. The purpose was to allow the fuel tank and vent system at the rear of the car to be pressure tested for leaks. The 98 system is different than the later years, because the 98 kept the steel fuel tank, and mounted the new design rectangular canister outboard in the previous location. In 99 they went to the plastic fuel tank, and seemed to integrate all the EVAP system and pressure sensors on top of the plastic tank.

I share your concern for foreign objects entering the system, but I can't find any evidence of a mitigating device.

In my case, when I deleted the canister (car became dedicated "track" car) I bundled the tank line and the purge line at the opening in the inner fender liner, and tied a piece of very fine knit fabric over the bundle with a plastic cable tie. The purge line wasn't connected to anything, and the tank vent line, still connected to the tank via the pressure control valve, emitted the fragrant odor of 116-octane VP Fuel C16.

From a practical sense, is a 20+ year old carbon canister still functional?

 

I will probably just zip-tie something to the tube. Still curious that the diagram does not even show the tube that is actually there. As far as functionality, I do not smell any gas in the 1 car garage I keep it in so I will keep it for now. Easier than removing. I can smell gas from my snowblower in my bigger garage until I drain it for the year.
Thanks for the info.