Can someone tell me what the fuel(?) lines that zig-zag in the back of the rear wheel wells are for? I am also having a hard time convincing myself what the 3-port valve between the fuel pump and fuel filter does. Shop manual calls it "air bleed valve" or "non-return valve". If someone could shed some light on this item too, I would appreciate it. Thanks
Dave

 

You're probably seeing the hoses and pipes for the fuel return system, as the fuel return valves are in the rear wheel wells


The non-return valve screws into the air bleed valve.

The non-return valve simply prevents fuel from draining out of the the fuel supply line so the fuel rail doesn't need to be 'refilled' after the car sits for a bit.

The air bleed purges air out...but I'e never opened one up to see what makes it tick. From memory, the air goes into the vent system

Cheers
DD

 

LT1 Dave -

I was teeing up to post that exact same question about the fuel lines in the rear wheel wells. Indeed as DD said, I thought they were part of the fuel return circuit, but seems pretty odd (well, it IS a Jag) that they would have the line come OUT into the open air, only to be run BACK into the innards of the car. Also, I was amazed that they were right there behind the wheel to catch every rock, stone and ice chunk kicked up.

Also in the wheel well is the access to the return valve and a round access panel for the its wiring to get it back INTO the car. But the wiring itself is exposed between those two panels for about an inch or two. But I guess they had to put things where they needed to go to route the lines and wires.

I am thinking the fuel return lines had to come out into the well in order to have a bend(s) put into them to make whatever curve they had to make to get back into the car?? Odd thing on my car is one well has about a 6 inch long U curve (picture), but the other well has a diamond shape. I am not sure which shape is factory correct, but implies one of mine was replaced at one time? Or maybe the two shapes are another Jag oddity.

 

Spot on ! I had a Series 3 for 14 years and it was obvious the designers had smoked a bit too much of something when designing certain aspects of the car. Most was pretty good, it was the buils quality that was total cr*p Ford had to spend the US Defense Budget to put the quality aspect right.

 

I'm going to answer my own question about the fuel lines in the rear wheel well. I rolled around under the car and traced the lines (they "T" to each other) into the boot through the front bulkhead and disappear into the boxed section between the top of the boot and bottom of the rear windscreen. The route is the same for the line in each wheel well. The other end of the line goes to the front right of the car and attaches to the charcoal emissions canister. I looked in the emissions section of the shop manual and there is a very nice picture and description of these lines. Seems there are vapor separators located in the rear windscreen side pillars which manage excess fuel vapor. They condense the vapor, with the raw fuel returning to the tank and the lighter vapors drawn into the charcoal canister and then into the engine. The vapors from the tanks come from the small hose under each filler cap and a second line connected to the boot side of the fuel tank, accessed inside the boot.

I'm not even going to try to understand the "why" of this arrangement. I don't think I've ever seen a setup like this on any other car. If Jaguar was happy, so am I.

 

When I removed the interior from my S2 I had noticed these fuel lines in the rear deck and had to explore as to what they are as well.

Mine were rusted and had huge holes in them, presumably from the window leaking water on to the rear deck.
I can't fathom that these lines had burst and then caused the rotting around the rear window, I imagine it was the other way around.

Since my car isn't going to end up using these lines, i removed their counterparts in the wheel wells and trunk and called it a day.

 

After more reading and these posts I guess the post title should be “Fuel vapor lines in wheel well”

My previous post was based on ignorance thinking these were the liquid fuel return lines

 

You're right about the better post title, but it was me that asked the original question and was ignorant of what kind of lines they were, you're in the clear. I might have researched and investigated a little more and wouldn't have had to ask the question at all.
Dave

 

I thought we were talking about liquid lines as well. But, no matter ! It all comes out in the wash.

The vent system is a little weird. There are a couple of pressure sensitive valves behind the RH front wheel that come into play. They open at xx-pressure and close at yy-pressure. I understand it while I'm reading about it in the ROM....but within 5 minutes it's all turns to vapor in my mind again!

Cheers
DD

 

I see the original method of tank venting very complicated and just waiting to cause some kind of problem. I'm interested, how did you vent your tanks and did you keep any type of emissions to bring the fuel vapors into the engine. Thanks for any comments.
Dave