Fuel Tank Cap (lockable)

I think I may have one. I'll check when I get home

My GT5 has a lockable cap it is a Motorcraft FC-768 for 72-75 Ford, Lincoln, Mercury.

Julian

Hi Julian, many thanks.

best
Jan

Just to round this thread off (or turn it back on to the initial track) I purchased a Lockable Gas Cap which is now in the mail. I used Julian´s reference for a Motorcraft Cap except that I could not find one from a European seller that was not vented. I will see once it arrives if I am able to seal that vent off somehow.

Thanks
Jan

quote:

I will see once it arrives if I am able to seal that vent off somehow.

Why do you feel it needs to be sealed?

Not an emissions issue on our cars. Tank came with one vent.

I can see nothing wrong with two vents?

Larry

quote:

Many owners have said, "when the low fuel light goes on, stop NOW for gas or enjoy walking".

I did my restoration going on 10 years ago now, so my memory is a bit fuzzy on this. But I seem to remember being able to adjust when the sending unit sent the signal to the low fuel light. There are 2 rheostats in the sending unit. One for the gage and the other for the light. By carefuly bending the tab for the light, you can adjust when it comes on. Mine comes on at about 1/8th of a tank now. Can anybody clear up my fuzziness? And I also apologise if I hijack this thread!

quote:

Why do you feel it needs to be sealed?

Not an emissions issue on our cars. Tank came with one vent.

I can see nothing wrong with two vents?

Larry, the way the Tank/Filler Neck is constructed on the Pantera does that Fuel can find its way up to the Cap under driving when the Tank is full or close. And I just don't want it to overflow and run down the overflow pipe and on to the Tarmac. I believe that is why they designed it to be vented via the blue Tank on the RH side of the Engine Bay and not via the Fuel Cap?

quote:

I did my restoration going on 10 years ago now, so my memory is a bit fuzzy on this. But I seem to remember being able to adjust when the sending unit sent the signal to the low fuel light. There are 2 rheostats in the sending unit. One for the gage and the other for the light. By carefuly bending the tab for the light, you can adjust when it comes on. Mine comes on at about 1/8th of a tank now. Can anybody clear up my fuzziness? And I also apologise if I hijack this thread!

I recently pulled the Fuel sending unit to modify it with a larger diameter tube. Went from 5/16" to 1/2" Pipe to secure no restrictions to feed the new RobBMC Fuel Pump. My point is sorry, there are not 2 Rheostats in the sender, there is one and then there is a set of Contacts for the low-fuel Light. And as correctly mentioned it is very easy to adjust the position for when the Contacts close and illuminate the caution lamp on the gauge. I have about 50Km left when light is steady on.

OK, I see your point on the fuel sloshing issue. I hadn't thought of that.

As for the blue canister you referred to, that was the tank vent I was also referring to. It was part of the Ford emissions system and the charcoal in the canister was designed to collect the VOC gases released through the gas tank vent.

Is that hose still in place on your car to serve as a vent?

Larry

yes the blue canister is still hooked up to the Tank vent

I think that IF you want the charcoal canister to remain connected and functional, then you need to use a vented filler cap and it needs to be connected to the engine intake manifold vacuum?

Look at the connection diagram. The venting of the tank is done by connecting the hose from the canister to the vacuum of the engine intake.

It is providing a negative pressure to the fuel tank itself.

It will be drawing fresh air in from the vent in the cap into the void in the fuel tank, then flowing the air bound vapors through the "tank vent mechanism" through the charcoal filter, then into the intake manifold.

First off, how much this effects the idle quality of the engine is suspect to me? Second, the engine sees this as a vacuum leak. It is effecting the air/fuel mixture strength to the engine.

My tank vent is not attached any longer to the intake manifold. It is just vented to the atmosphere like a vent cap would be.

Why would you WANT to use the emissions venting system if you did not have to? That was to satisfy US emission regulations for a manufacturer when the car was new.

Who is going to check you on that now? Contrary to other reports in the "Paranoid Press", Big Brother does not exist here in that sense of the term.

quote:

Look at the connection diagram. The venting of the tank is done by connecting the hose from the canister to the vacuum of the engine intake.

It is providing a negative pressure to the fuel tank itself.

You are confusing your self. The canister is not connected to Vacuum it should if anything be connected to the Air Filter. But as in your case mine is just vented to the Atmosphere with a hose that is strapped to the Frame forward of the Right Wheel Well.

I don't have access to my car now, but I agree with Doug.

Charcoal canisters generally collect fuel vapors when the engine is off, and then suck them into the induction system when the engine is running.

You should have two lines to it - one from the fuel tank, and one to the air cleaner.

Bosswrench says they typically are ineffective after about 5 years, and he just runs the tank vent line directly to the air cleaner.

Rocky

I am not confused. I removed that crap 1,000 years ago and threw it over the fence at my neighbor. What he did with it I don't know and I don't care.

He probably sold it on ebay?

Doug has been sniffing way too many fumes after he removed his canister....

The charcoal canister should be connected to the air filter NOT to the intake manifold (and a source of vacuum). You don't want the engine to be pulling vapor from your fuel tank for a number of reasons; it can impact air/fuel ratio, if your tank isn't venting through the cap you can collapse it (this has been done!) and what if a backfire occurred?

The canister's purpose was to capture fugitive emissions as the fuel sloshes around/tank filled etc., but when you think about it the charcoal will load up and then it's pretty useless, especially after 30-40 years!

Most people have done away with the canister and installed an anti rollover valve in the line that allows venting but stops the tank contents emptying should a rollover occur. Here's Hall's solution that replaces the outlet on the tank and can be piped to the air filter still.

http://hallpantera.com/cgi-bin...ntera-inc&item=22057

Julian

Let me clarify

My Tank is vented/connected to blue Canister and
Blue Canister is vented to Atmosphere. The Tank needs access to a source of Air to replace the volume of the Fuel being sucked out.

Blue Canister was previously vented to Air filter and NOT to engine vacuum/suction which would have created a non-desireable vacuum in the Fuel Tank!

quote:

Originally posted by Joules:
Doug has been sniffing way too many fumes after he removed his canister....


http://hallpantera.com/cgi-bin...ntera-inc&item=22057

Julian

Well close but it was actually Sunoco racing gas. Got too close to the pump and got a big a wiff and couldn't remember the entire weekend. Was like I got hit in the head with a 2x4, which come to think about it, has happened a few times too?

Unfortunately this has long lasting residual effects. As soon as I read this post and I remembered, I got a really bad migraine from the flashback...but wait, I can't remember so how can it be a flashback? Jee-ze?

Jan

I just wanted to mention admiration for the excellent job you did replacing the 5/16" fuel line with a 1/2" fuel line. Thanks for taking time to share the picture. I hope others benefit.

Thanks to others for getting the thread "sort-of" back on topic. Please guys, don't take threads off topic, start a new thread or PM your question to whomever.