Darn close, Grant!

I just checked. It's brown/slate


Cheers
DD

 

I woke up this morning and noticed a leak under the car. I opened the trunk and it was coated with gas. I am going to remove the panel in front of the fuel pump and see if that is leaking. Maybe my pump is humming but leaking gas? I'll post back later with photos. We watched and checked for leaks before starting and I didn't see anything, but after sitting overnight I have a gas leak somewhere.

 

I reckon this needs some very careful checking prior to any more attempts at starting it.

These cars can go up in smoke without any outside assistance, so please be careful.

Remove that cover panel under the battery, check the pump carefully, especially the base section that inserts into the alloy casing, as there is an o/ring seal in there that stops leaks. It is NOT a seperate part, it comes WITH the new pump, all sealed, ready to go. This may have dried out and cracked and is now leaking.

The small "sump tank" under the battery is a very likely place for the leak, as it has a seal in the top, under that ring plate, and will have dried up by now for sure. These small tanks also rot out, well documented.

The hose from the main tank TO the small tank also leak, BAD.

The main tanks rust inside, and the flakes of rust block the outlet that leads TO this hose and thus stops the gravity flow of fuel TO the sump tank, and that leads to NO fuel to the pump, and so on.

The HI pressure hose out of the bottom of the pump to the filter, then to the brass elbow up in the corner under the battery is also a known leaker.

The main tanks also rot out and leak into the foam matting it sits on, then outside the car via the holes in the boot floor.

If the tanks prove OK, then all the hoses, 8mm HI pressure, and 12.5mm LO pressure need changing. There are some smaller "vent" hoses in there also that should be renewed. These are ALL generic hoses, so "off the roll" hose of proper spec is all you need.

The seal on the sump tank lid and the fuel sender unit need changing. They are the same size, and are NOT Jaguar specific. A tank unit seal for a similar age Ford, or GM will suffice here.

That should sort the fuel issues in the boot.

The HI pressure hoses in the engine bay SHOULD be addressed also, simply due to fire risk again.

 

Today I cleaned everything up so it was dry, and put more gas in the tank without trying to turn the engine over to see if the tank leaks without pressure to rule out something leaking on the high pressure side when I try to start it.

Unfortunately, it looks like my tank is leaking. I have gas SLOWLY seeping out from under onto the foam/under the foam, but it seems to be only at the bottom of the tank somewhere that I can't see, and gets the foam wet (not the surface of the rubber on top of the foam). It looks straight forward to remove the tank, unless I am mistaken? I see 4 bolts holding on brackets, and then a number of fuel hoses. What is the best way to go about replacing a tank? Perhaps I should do a compression test to see if its worth saving this car. Otherwise, its rust free and is fully documented. The best part is that fuel tank was replaced in 1999. Do they really only last 10-14 years? That's a little ridiculous. There must be a better way... I don't want to spend money replacing a tank if I can't hear it running first, but maybe I have loose rusted metal blocking the lines somewhere. Maybe the POR-15 kits will do the trick, or is that advised against?

Also, if I have air in my fuel lines, how long would it take for me to crank the engine over until it finally starts if I put fuel in? What is this "vapor lock" that I've been reading about?

 

OK, tank out is no big deal, and although fiddly, not hard in the big scheme of Jag repairs.

Coming up from under the car, on the RH side of centre, is a "pop rivet" that holds a bracket of some sort, and the top of this rivet is covered by the foam mat, and over time it rubs through the foam, and then rubs a hole in the tank.

I flattened that sucker down, and covered it with RTV, waaaaaay back.

Of course you could have a tank that is simply rusted out again, which does/will happen from lack of use, and improper storage.

It needs sorting obviously.

The "vapour lock" you hear about is after a "hot" shutdown, and then a restart after about 15 minutes, and the fuel boils in the rail, and that is a "vapour lock". I think you are a loooooong way from that exciting experience.

When you turn ON the ignition, and the pump whirrs for its required 2 seconds, the fuel system is deemed PRIMED, and ready for starting. OK, after storage time, and NO fuel, etc, etc, then the ign ON/OFF about 4 times should well and truly prime that system.

Undo the fuel line at the RH side of the rail, poke it out over the guard, turn the ign ON, see how much fuel sprays out of it. It should be significant.

Once you have fuel up front, then you have to establish that the injectors are "actually" opening as they click. They can "click" but not actually open internally, so the car will not run.

You say you have spark, so give each air cleaner snout a spray of starting fluid, and see if it fires up for a few seconds. That should determine a sound or sad engine.

 

There are 2 ways fuel tanks runs on XJS, the "inside out" and "outside in".
Of your tank rusted from the outside, due to accumulation of moisture inside the foamy pad, then you are ok. All you have to do is clean the surface and solder the pinholes, any radiator place can do it for you. NExt step would be coating your tank from the inside with polymer, kit can be bought online, at Eastwood, or many other places ~$60.
If your tank is rusted from inside out, then she is most likely trash and needs to be replaced.
I just replaced my tank, after finding out that mine is all rusty and paper thin from the inside. Tank I got from a friend was excellent on the inside, but had 8 pinholes on the bottom, from external rust going all the way through.
Unfortunately, any rust inside tank will cause eventual clogging of injectors, because microfilters inside those are more fine, then the main filter in the trunk.

Here are some pics of my erotic fuel tank adventure.















P.S. treating and coating goes for the surge tank as well.

 

if it has been sitting for a ehile i would check to make sure the injectors have not seized. you can do this with a car battery and two wires. hook wires to battery then take off the plug from injector. on injector there are two pins touch one wire to one pin and the other wire to the other pin this should activate the injector and you should hear a clicking sound . if no sound keep putting wire on and off and it may come unstuck. if no clicking they are seized.... first thing i always check when getting a v12 that hasnt run for a while

 

I finally got the fuel tank out today. It has rusted from the outside -> in, and there are 3 small holes 1-2mm in diameter on the bottom nearest the tail lights on the same panel that you covered with solder. The interior looked mostly shiny. I bought some POR-15 marine clean and sloshed that around the tank interior for a few minutes with all openings duct taped. The liquid that came out was dirty. I will try cleaning the tank interior once again. I used a sponge on the exterior with marine clean. How did you get yours so clean? I'm worried sand paper or a steel brush will cause sparks.

I have read that I can use POR-15 paint to seal pin holes. Has anyone done this? What you do, is treat the rusted surface with Marine clean, then metal ready, then POR-15 paint. With the paint still wet, a fiberglass cloth is applied, and then painted once more. I also bought POR-15 tank sealant (US Sealant) which I plan to apply but was worried to once I saw all the channels inside. If you did it with no problems, then I'll try too. I'm not sure if the POR-15 paint or radiator place soldering is better. I'm worried the solder might crack. I've had very good experiences with POR-15 paint, just never tried it to seal pin holes.

Also, my fuel gauge sender was completely seized and I'll need to buy a new one (is that even possible)?

This is the fiber cloth:
http://www.por15.com/POWER-MESH-REIN...BRIC_p_75.html

I forgot to ask, what are the specifications for the fuel lines coming out the tank? I'd like to replace everything while I'm in there. I'm certain much can be generic fuel injector line with injector clamps, but a few (2?) had fittings that screwed into the tank. I'll also need a new fuel sender gasket.

 

All fuel lines hoses have to be replaced. I used standard US made fuel hoses for carburetors and fuel injection, where high pressure was required. NAPA, or even Advance auto parts will have all the sizes you need.
Once your tank is rinsed, you should not worry about sparks, I used wirewheel on grinder to get my tank cleaned from the outside, which opened up few more holes under rust scabs.
You can use any fuel resistant patching from the outside and do not have to solder like I did, as long as you apply tank coating from the inside.
If you just want to plug the holes and move on, I'd use soldering, since it is the most reliable.
After I was done, I painted tank with pickup truck bedliner spray, because it is the only fuel resistant coating in a spray can that I found.

Almost forgot, I have spare fuel sending unit in very good shape, so if you do not find one new for about $55, let me know.

 

A bit of an update:

I finally got around to removing the tank, cleaning, sealing and painting it. I put about 2 or 3 gallons in it and tried to start it - no luck. I no longer hear the fuel pump buzzing, so I checked the connections and noticed a ground that was lose near the battery. As I tried to tighten the screw, the head broke off so I'm going to have to extract that and buy another screw. For now I will clean all grounds near the battery and try again. Strange, but the wires are grounded to a painted chassis. I wonder if the paint is causing poor conductivity but it appears to have come this way from the factory. I will update you all once I fix this ground that I broke :-/

 

I hope I am testing this correctly, but I just connected leads from the fuel pump directly to a known working battery. The pump ticked once and that's all. It didn't buzz or make any noises that it is moving like it used to.

I have about 2-3 gallons of good fuel in a re-sealed tank and sump tank. Was I supposed to prime it somehow before trying to start the car? I assumed gravity would do it's thing since the pump is lowest. Now I assume I have to re-drain everything to pull the fuel pump? Worried I'll have 3 gallons of fuel pour out if I undo the hoses attached to the pump. Attached is a photo of my test setup.

Does the fuel pump brand matter when selecting a new replacement? Maybe at 80,000 miles I should replace the fuel pump relay also, but as you can see my test setup completely bypassed everything else that could fail electronically (ecu, relay, fuse).

 

Pump is probably failed, no surprise there. If it ran with brown sludge it is probably worn out internally, just like mine was.
I installed known good Bosch pump from Ford F150 pickup truck that I had laying around and it works perfectly fine, but even the original replacement is not that expensive. You can test with any inexpensive pump that makes 40+ psi.

 

I thought I would take over this post as I ended up buying this car last month. The good news is it now starts, the bad news is it will only run for a few seconds. I suspect my primary issues here are:

1) A few stuck injectors; which I am going to shock with a 9 volt battery if I can ever get the connectors off

2) the vacuum lines on the passenger side are not connected. I need to buy some hose and get them re-routed

I've already replaced the battery, fuel pump and rebuilt the ignition amplifier. More fun to come

 

Keep us posted Greg. Have you some photos of the car