I'm replacing my fuel lines, and while I totally understand the precense of the main fuel line, the return and the short ventelator line that runs fromt he tank for about 1' into some round black plastic thing just beside the tank.

But what is the purpose of the line that runs from the tank all the way to the front driver's side of the engine bay where it is just open. Is this something that is supposed to be like that or has somebody removed something from my car in the past?

Any help would be appreciated!

Cheers,

Si.

 

Judging from the description, that's the line that is supposed to lead to the charcoal canister

 

I agree. Sounds like the gas tank vent. it should hook up to a black cylindrical object(charcoal filter) that filters out the gaseous vapors before being vented to atmosphere.

 

Yes it does vent the tank, however, it doesn't vent to the ambient air. It gets drawn back into the intake so it can be burnt off. All part of the EVAP system.

It's the size of a Folgers coffee can. Black. Has a couple of vacuum lines off the top. It's up front in the "driver side battery tray." Really can't miss it if it's there.

 

Well the drivers side battery tray is totally empty, so I guess that part of the system is gone.

Given that I have a holley 4160 carb with free flow air filter, should I just block this pipe? Or what?

Simon.

ps. In the UK emmisions levels is all that matters, so I don't have to keep the car at all stock for emmisions equipment, if that makes a difference.

 

Don't block it. That is the absolute last thing you want to do.

A replacement canister can be had at parts stores, however, I do not know how aundant those are over there. The charcoal can really doesn't effect any of the measured emissions output, it just helps fuel economy. I suppose you could put a filter over the end or something like that. As long as vapors can get out. The best thing to do would be to just try to get a replacement. But, like I said, they don't really effect emissions output.

If you do a search, you can look up the filter over the end technique.

 

Okay, so if that pipe is just to vent the tank, what is the exact purpose of the short fuel tank pipe that goes to some 2" round black plastice thing at the rear. I thought that was the vent.....

Thanks for your help with this!

Si.

 

Thats the flatuation (named for the crude and obnoxious sound it makes when it fails) valve. Well, fuel vent valve to be exact. It's purpose is to vent pressure when it reaches an excessive point. It also (and perhaps more of a main purpose) is to allow air in as fuel is taken out. This eliminates the possibility of a low pressure situation in the tank, and ultimatly, implosion.