Hello all
I've recently bought my first series 3. I filled both tanks up . Runs fine on the right tank (drivers side RHD ....UK ) . When I change to left tank after about 2 mins idling speed fuel starts hosing through a pipe underneath the car just forward of the rear undertray edge and before the IRS. It is metal not a flexi. If I turn engine off and switch to right it eventually stops. The flow is such that it will empty a full tank in a few minutes. . Fuel returns to both tanks. Left opens with a whoosh right doesn't. I think it is air inder pressure in left rather than air sucking in . I've trawled forums and Internet. There is loads of stuff about faulty canisters in the front wheel well in USA cars with emission dystems but this does not apply to my UK car . I am stumped. Any help advice welcomed I've got a Haynes manual and online diagrams I can't for the kife of me see that inder car pipe on any of them. Should it be there. Has somebody in the past just left it unconnected to solve a problem with the left tank ???

 

sounds like a return line is broken, cracked, disconected.......something......
thats my guess.
Haynes manuals are worthless!!

 

Attached are some diagrams that may help you identify which piece is broken/leaking.

 

Thanks, John.


At this time, the fuel system ion my car is fine. But, these diagrams are helpful. I saved them.


Leaking petrol/gas is nothing to tolerate.


Some years ago, my son was under his Ranchero with the rear wheels off welding. Yowee, I was inside, it was night. His truck was right in front of the open garage!!!He burned a hole in the gas tank. Furious fire. The garden hose did nothing good.


I told wifey to call 911 and ran out there in my pajamas!! His pal was there with his little 4x4 pickup. I yelled to pull in front of . I grabbed a chain and made a quick hook up. He jerked it away. Right at that time the fire truck pulled up. quick acting guys put a fine fog stream on. Out in a jif. they checked the interior of the garage. The Capt. opined that the wood was on the verge of ignition. Indeed, some plastic stuff on the tool board was melting!!!!


Luckily, no0 one hurt and the only issue was a charred tail on the Ranchero. Oh, and a holed tank!!!


Carl

 

one way to investigate where the leak is, is by removing the rear quarter panel and visually checking the underside of the tank, but to remove the quarter panel entails removing the quarter section of the chromed bumper, a big disassembly job.

in LHD cars, your Driver's side tank is the Passenger's Side tank, and most usually, it is the tank that leaks. Looking at the car from the rear, the Right Side Tank and its hardware are usually the leakers.

but leaks can happen in a number of places; Check the following before going to the last resort quarter panel-bumper removal:

1) remove the right driver's side tail lamp Lens; (4 small screws)
2) then remove the tail lamp housing itself, (3 large screws), and move it to the side so you can look in with a flashlight to see if the Sender Unit in the rear of the tank is leaking. There will be two wires connected to the Sender Unit, which is mounted to a round cap. This is a possible leak area when the tank is filled. If dry, reassemble.

Next simple check would be to jack the car and remove the rear tire, then remove the little panel behind which there is a Solenoid and rubber hoses. This is another potential leak.

Look at the PDF file posted above and remove that small panel, it comes off by removing screws. you might get it off without removing the tire, then repeat what you did to see if you observe any leakage.

 

I can vouch that tanking the tanks out is a fairly big job. Took me about 6 hours to remove both and about 8-9 to reassemble. I don't want to do it again if I can avoid it.

 

Thanks everybody . The exposed pipe underneath my Seies 3 goes off to the right (drivers side on my UK car passenger side on US car ) and disappears up towards the tank oh that side but only spews petrol /gAs when I try to use the opposite side tank ( drivers US /passenger UK ) there is no pipe going off to the left tank only the right but only leaks when using left tank

 

I wonder if it is your switch over valve thinggy. Mine did similar when I got it. The return flows into the correct tank, but the switching valve is not changing. so for example, if on right tank, it will draw and return to right tank, and when switched to left, it still draws from right, but returns to left, thus overflowing the left tank quickly. Worth checking me thinks...

 

Mine is acting up, very pausable.

 

Before we go further, do you have the 4.2 fuel injected engine? Or the 3.4 engine on carburetors? The pipes and plumbing are entirely different between the two.

Cheers
DD

 

Hello Doug

It's the 4.2 fuel injected. Today I took off a rubber hose off a metal pipe inside the boot /trunk on the left hand side at the top . The metal pipe looks as if it goes in to top of left hand tank . The rubber bit goes under the parce shelf heading for the right hand side . I started car at idle. Switched to left tank. The following happened. Car kept running. The stream of fuel underneath did not appear. The metal pipe going in to the left tank was uv king in air . Opening the left fuel cap did not result in a whoosh of pressure escaping ( definitely has been positive pressure inn there not a vacuum ) my friend reckons the rubber pipe that attaches here is breather and is blocked somewhere. I was quite pleased sorted I thought I'll clean out pipe when I get a moment but had to do a message . So reattached rubber hose and switched to right tank which works and doesn't cause a leak. NOW find right tank has filled itself from half full to full . I don't think there is a tank or a pipe leak I think it's valves / blocked pipes or has a previous owner overhauled the system and cobbled it back together incorrectly. Any further thought s appreciated

 

I'm trying to digest what you've written

Meanwhile, this might help.....

Fuel Tank Switchover Checklist, Series III XJ6


Cheers
DD

 

I think Richard_gib gas it right. Your switch is changing the fuel line but not the return.

 

That was my gut feeling from the beginning ..... gas tank overflowing due to a faulty return system. But KJTs remarks that the fuel is coming from a *pipe* has me a bit stumped.


Cheers
DD

 

yea I agree, that is a stumpper. I guess a picture would help us figure out what "pipe" is being referred to. If we could see the pipe then we could identify it.
I don't know if I mentioned this in another thread or not, but I just replaced my changeover valve about a week ago. working what I thought was alright, untill the other day when I did the tank rinsing with water. Im driving along on the one tank and had water in the other one. Every mile or so I'd jump out and let out about a gallon of water. I was thinking it would slosh around as I was coming home. So I'm almost home and it stalls out like I ran out of gas. Well the valve just went back to default I guess and switched to the tank with water and I was fulll of water throughout the fuel lines. What A BIT#@!!!! Glad I had a can of starting fluid to get it going a few times untill it pumped all the water through. Also glad the cop didn't stop me as I rolled through the red light to get to a good plase to pull over.
Today was a whole different scenario though. Ooooh, Ill tell this one another day. I need a drink to forgive myself first!

 

Hopefully phot attached

 

By the way that isn't the length of the pipe . It's a plastic red straw stuck in to it as the pipe sticking out is only about 1inch long. If you're u stick your hand up the leading edge of the valance you can feel it going horizontally off to the right There is nothing I can feel comong from the left. Anybody any wiser ?

 

Is that pipe supposed to be there ? If so what does it do. Bear in mind this is a UK car so no USA gas emission /atmospheric recovery stuff on it

 

I'll go look at mine here in an hour, and get back to you.

 

Go back to posting #3 and open the link to the parts catalog illustration. Now look at the return pipe part number CAC2474. It runs (primarily) left-right in the area you're talking about.

Could that pipe be broken, and you have the red straw stuck into one of the broken off stubs?

Cheers
DD