“Free to a Good Home” XJ-S V12

The short fuel hoses were replaced when I had the injectors out, I knew that was a fire risk and wanted to avoid it. Waiting on one fuel feed hose that is very cracked, then it should start.

The car came with a printed copy of Kirby Palm's book. I was already familiar with it, since I'd been wanting an XJ-S for a long time. One of the previous owners (probably not the guy I bought it from) seems to have know what he was doing, for instance the distributor is not seized. It rotates backwards and then springs forward just the way it should. I ordered a new style filer for the surge tank, only to find that it had already been upgraded. I replaced it anyway.

I'm getting ready to do the fuel injector hoses on my xj. Definitely a weird setup.

Are the individual injector hoses a different size than the main line hose? Or did you just run out of hose?

In reply to Robbie (Forum Supporter) :

The main hose is a mixture of metal pipe and rubber hose. It's got screw connections at both ends, with a 90 degree bend in the hard line. I'm not sure how the rubber hose is attached and it's not really an area where I want to experiment. I think it would be too easy to end up with a massive leak if I tried to change it myself. 
Here's the hose in question:

In reply to garethashenden :

Replace all the vacuum lines.  Yes the one going back to the computer too!  Then watch the how to tune Jaguar V12 fuel injection on U tube I think it's in 3 parts. 

TED_fiestaHP said:

  I always liked these, somehow I haven't bought one.  I will follow along, should be a interesting build.

     I have heard it is set up as 2 six cylinder engines, 2 separate fuel injection systems.  But I have never worked on one.

        I does look rather complex.

           I did hear the air filers limit air flow, might be some untapped potential available.

 

 

It's a proper V12 it's just listed as Bank A and Bank B for simplicity.  Mechanically they are massively over built.  Most crankshafts weigh in that 20-30 pound area. The Jaguar crankshaft is made from the finest grade high strength Forging and then hardened.  ( oh, and weighs 78 pounds) Massive 3.00 mains and 2.30 inch rods!   A V8 may have as few as 10 bolts holding on a head. ( 1 side). The Jaguar has 34 studs that often go all the way down to the mains  ( (1side) 

The block is an Aluminum die casting ( stronger and more dense than a sand casting)   heads are aluminum  valve covers are finned aluminum. To get the same quality components in a typical V8 you'd spend $20,000 just for the parts. 

Don't be intimidated by all the hoses etc. a lot of them are for HVAC.  ( the fuel line is even air-conditioned)   The  fuel injection system is straight forward once you understand it. There is a 3 part series on U Tube on how to tune it up.  Watch it a few times until all the lite bulbs go on in your head.  It doesn't have the OBD2 port so you actually have to grasp it but he does a nice job of explaining and displaying things.  It's actually simpler than a lot of modern systems.  just harder without the OBD2 port. 

Yes, the air filters cost some horsepower but the reason is to make the Engine  Really, Really quiet ​​​​​​ and get better fuel mileage.  
You can use the stock filter assembly just remove the air horns that go into it and replace with a big hose picking up air from in front of the radiator. That will pick up a lot of power. 
There are alternators that don't look like they came off a Bus and if you don't live where you have a visual system check the air pump can be removed which will greatly clean up some of the messy ness of the engine.

With a reasonable size alternator and no air pump, you can remove that ancient York A/C compressor and replace it with a modern one on the side of the engine. Suddenly the engine opens up and you can see the beauty and simplicity ( plus changing  spark plugs is an easy 15 minute job instead of a 2 hour special wrench job ). 
 The big advantage is not only do you have commonly available ancillaries,  Now air starts flowing through the engine compartment and the engine runs cooler. You no longer need to air condition the fuel line. The battery won't cook itself to death ( and need a cooling fan)  

garethashenden said:

In reply to Robbie (Forum Supporter) :

The main hose is a mixture of metal pipe and rubber hose. It's got screw connections at both ends, with a 90 degree bend in the hard line. I'm not sure how the rubber hose is attached and it's not really an area where I want to experiment. I think it would be too easy to end up with a massive leak if I tried to change it myself. 
Here's the hose in question:

Do not go to your local dealer for those hoses.  See if Rock Auto has them or Terry's Jaguar, Moss motors etc.  I have a local hydraulic hose guy and if I bring him the hose he makes them for me.  

Don't go to your dealer for wheel bearings  etc bearing supply houses have them at a massive discount. 
 

In reply to frenchyd :

The nearest dealer is 2 hours away, SNG Barrett is 1 hour, so they're my initial go to place. They wanted $180 for this hose. Moss only wanted $90, but they're closed at the moment and not taking orders. Eventually I found it for $70 from Motorcars ltd in Houston. It's on its way and will arrive

I cut the air horns off as well as the front plate they attach to and it was perfect, quiet when cruising around but great sound when you stuck your foot in it.

Definitely worth your time to adjust the throttle body gap and the linkage all the way back, that made a pretty big difference on mine.  There's a how-to in The Book.

Sounds like you got lucky, lots of well-thought-out work.

Oh yeah, don't forget that vac hose back to the computer!

These engines are ridiculously overbuilt.  I laugh at all the idiots who swap in SBCs thinking it would make them more reliable, because they pull out the one unbreakable lump and leave the "reliable" SBC still surrounded by the rest of the stuff that breaks.  And yes, I'm considering the dropped-valve-seat issues in there because they are caused by the plugged radiators I mentioned before.

For the love of God while you're waiting for the fuel hose, pull that rad and get it rodded out.  And follow the procedure when you're bleeding when you reinstall.

I got the car to start!!
Added some fresh gas, reconnected the battery, turned the key and “Click”. The starter relay went click but the starter didn’t turn. I turned the key off, then back to on and I couldn’t hear the fuel pump running. So I pulled the starter relay, the main relay, and the fuel relay and took them inside to work on. With a 9V battery and an ohm netter I was able to check that all three were working. I cleaned the contacts and put them back in. This time the fuel pump came on when I turned the key. I ran it a few more times and then cranked the engine, it turned but didn’t start. A few more times and it ran very roughly at idle, but smoothed out with a bit of throttle. Encouraged, I decided to check the butterfly valves and idle control valves. The butterfly valves were very tightly closed with the throttle rods off, and they were pulling they valves even tighter. With this all adjusted properly so that the butterfly valves have a 0.002” gap, the car idled much better at about 650 rpm. It was still a little rough, maybe timing, maybe something else, but it was really loud! I turned it off and out my tools away, then started it up again. I’m amazed at how quickly it catches when you turn the key, but this time it ran badly. Worse than when I first got it to run with lots of blue smoke out the back and some coming up the sides of the engine. 
Then I realised what I’d done. When I changed the oil a few weeks ago I hadn’t changed the filter, because I used cheap oil and have been planning on changing it again once the car was running. But I put the full amount of oil in, so now it has a quart too much or so. The level on the dip stick is 1/4” over full. So I’ll need to fix this. As to why it’s so loud? Someone either started to remove the exhaust of didn’t finish putting it back on. All four down pipe flanges have nuts on them, but the flanges are at least 1/2” away from the manifold, so there’s a huge gap! I suppose I should really pull it apart and fit new gaskets, but I’m going to try just tightening them up first, it should help a lot

Awesome!  I remember on my car setting that throttle body gap and adjusting the linkage all the way back to the quadrant made a HUGE difference on mine.

Let us know when you decide to tackle the AAV....  :)

Made a bit more progress with the car. I decided to start working on the front suspension. All the bushings look original and quite worn, so they're all getting replaced. I'm going to have a shop replace the lower control arm inside bushings because I don't have the ability to unload the spring safely, but everything else I can do myself. 
The top wishbone was pretty easy. With the car supported properly and the wheel off, I put the jack under the lower ball joint and lifted until the upper bumpstops came off their rest. Then I undid the nut in the upper ball joint and lowered the assembly off the jack. With lots of help from the spring and a little from a crowbar, the upper ball joint popped out of its mount pretty easily. From there disassembling the upper wishbone and renewing all the bushing, ball joint and locknuts was very straightforward. 
The lower ball joint put up much more of a fight. First off, it's harder to get to, secondarily, I no longer have the spring to help me. Eventually, I removed the caliper and pulled the disk towards me to have maximum access. I removed the bottom cover on the ball joint and used a gear puller to separate the ball from the lower wishbone. This seemed like it wasn't doing anything until it suddenly popped out. 
Both the upper and lower ball joints were replaced with sealed new ones. The original lowers are rebuildable, but that seemed like an unnecessary amount of work, especially since the sealed ones last longer. 
Next I tackled the brakes. The pad had plenty of life left, but the disk was down to its minimum thickness. It wasn't undersized, but while I was doing all this work it seemed like a good time to replace it. The disks are attached to the inside of the hub, for the sole purpose of making it extra fun to change them. I undid the bolts holding the disk to the hub from the back. I'm so glad I bought an impact driver when I started this project, it makes things like that so easy. I pulled the hub off, dust cover, split pin, little crown thing that hold then pin to the nut, nut, washer. Then the hub itself. I put a flattened cardboard box underneath to catch any falling bearings, which was an excellent idea as the outside bearing immediately landed on the box. Much better than landing in gravel. The inside bearing came out fully assembled, which raises the question of were the rollers spinning or was the ring spinning? Apparently that can happen, but I didn't know that until after it was back together. I may need to revisit it. The new disk was fitted and torqued to the hub, then the hub was reinstalled. There's a rather complicated procedure for setting end float, or a much easier approximation. I went with the latter. While spinning the disk, torque to 25 ft lbs, then back off 1/6th of a turn. It seems to spin with the same level of slight resistance that I had before I disassembled it, so hopefully it will work. The caliper was next. All the seals (or are they just dust jackets?) on the pistons were torn, so I removed them, pulled out the pistons, removed the inner seals and cleaned out the caliper. There was some very light surface rust on one of the pistons, some very fine sandpaper cleaned it up quickly. New inner seals, new dust jackets, pistons back in, new pads, then back on the car. The hardest part was putting the bolts back in. They're hard to see and line up, but there are also several small shims that need to go between the caliper and the steering arm. Eventually I got it back together correctly I think. Finally, I fitted a new brake hose. The front brake fittings are some of the few metric fasteners on the car, just for fun. The inside end of the hose it fairly inaccessible, I can feel it but can't really see it. Eventually the nuts were undone, the old hose removed and the new one fitted. I still need to lock wire the caliper bolts and fit a new tierod end. Then the other side and the swaybar mounts and links. 

Needs some brake clean...

In reply to garethashenden :

You missed a couple of very important things.

First, you need to oil the distributor!?!??? I know sounds weird but it is important. in fact it is listened on the owners manual page 65 if my memory is correct. 
The reason you need to lube the distributor is there is no way for oil to get to the advance mechanism.  If you fail to lube the distributor the advance will freeze up and  as a result the timing will be off causing Engine overheating.  The engine will still start and run with the advance frozen. You likely won't feel anything wrong because a V12 is inherently smooth and powerful. ( more power and torque then a 454 of the same era measured the same way, shockingly ). 
 

Don't be scared, the process is simple. Describing the process takes a long time but doing it takes only a couple of minutes. First remove the distributor cap. To be safe you may want to mark your plug wires and where they go into.  Next check the advance springs and mechanism. Twist the rotor, slightly about an inch or so. You'll feel it go against the stop. It should snap right back smoothly.  Do it a couple of times to ensure it's still lubed.  If it hesitates or sticks you have to pull out the distributor, take it apart and remove the rust then put it back together.  ( again that's not complicated and describing the process is so much harder than just doing it). There are a few tricks involved so please ask. 
     In the center of the distributor is a hollow tube with a felt plug. First removed that plug Then you need to loosed the screw in the center a couple of turns. Just a couple.  
Now put some drops of oil in.  Commonly used is engine oil. I'm fancy and use synthetic 5-30 oil but since it doesn't mix with anything else and stays in the distributor you can use castor bean oil or  whatever trips your trigger. 
Give it a while to soak through,  I like to leave it overnight.  Then screw that center back down and put the felt plug back in. Now  give that  several more drops.  
 

Next while the cap and rotor are off I'll bet you haven't checked your vacuum advance unit either. 
I'll bet it hasn't  been checked since new and stopped working,  oh,  a couple of decades ago? 
replacing that will really help on acceleration. 
 

Darel said:

I cut the air horns off as well as the front plate they attach to and it was perfect, quiet when cruising around but great sound when you stuck your foot in it.

Definitely worth your time to adjust the throttle body gap and the linkage all the way back, that made a pretty big difference on mine.  There's a how-to in The Book.

Sounds like you got lucky, lots of well-thought-out work.

Oh yeah, don't forget that vac hose back to the computer!

These engines are ridiculously overbuilt.  I laugh at all the idiots who swap in SBCs thinking it would make them more reliable, because they pull out the one unbreakable lump and leave the "reliable" SBC still surrounded by the rest of the stuff that breaks.  And yes, I'm considering the dropped-valve-seat issues in there because they are caused by the plugged radiators I mentioned before.

For the love of God while you're waiting for the fuel hose, pull that rad and get it rodded out.  And follow the procedure when you're bleeding when you reinstall.

The Jaguar radiator is a very sophisticated radiator. It's a double pass radiator which basically treats it like 2 radiators. In one casing.  And I second the comment about following the procedure when bleeding it. Read it and read again.  A lot of "overheating issues" are just doing that wrong. 
 

Please please PLEASE do some form of muffler delete on this car.  That big V12 sounds incredible and the world needs to hear it.

I've always loved these cars.  I'm not brave enough to own one myself (unless I got it for $100!) but I love them.

posting 'MORE' because I want more V12 threads in my subscriptions... 

In reply to infinitenexus :

There are plenty of great value  V12 cars out there but not for flippers.  V12's like any car of the mid 1970's to 2000 era are cursed with complexity and pollution control issues. It didn't matter what brand, or how many cylinders, 12, 8, 6, or 4 they all were cursed. 
Not so much because of pollution control. it's just that there really wasn't any standard, best practices way to do it. We had a lot to learn. Don't use rubber hose for high pressure fuel lines being a big one. 
Car-B-Ques (cars burning on the side of the road) were all the rage back then. Vacuum lines that cracked and leaked. And heat!!  Air pumps and timing altered to minimize pollution also created hot running cars.  Add A/C, air pumps, bigger alternators, more and more accessories hoses running all over the place.  Some factories covered The motor with plastic coverings. And cooling air was trapped into smaller and smaller engine compartments. 
Didn't matter what brand. And factory training only covered a few guys. The rest of us Monkey see monkey do backyard mechanics had to slowly figure it out ourselves.  

Once  OBD2 came out and fixing became a matter of plug and play,  car stuff got fun. Until then we'd replace parts until magic happened and it fixed what what was wrong. Or give up and Junk perfectly good cars.  

Those are the great bargains.  Open the hood of a Jaguar V12 and it will terrify most mechanics.   But U tube has a 3 part series explaining the simple fuel injection system. And it is simple compared to a 4 barrel carburetor .  
Kirby Palm has a on line Free downloadable book to guide you through Jaguar XJS V12 ownership.If you're willing to do your own work  ownership is not only possible but affordable. A lot of parts are available  at places like Rock Auto, BillTerry's  Jags Moss Motors etc etc. 

Plus  junkyards are full of lots of good parts because the owner couldn't find a mechanic that understood how to balance the throttles or replace a defective sensor. 
 

Here's the really great news!  Most transmissions are made by GM The good old GM Turbo 400 ( in a Case for Jaguars ) just like Cadillac, Olds and Buick had their own cases. The rear end is a good old Dana 44 or the Salisbury version. 
 

The best news of all.  That V12 is extremely well built. Unbelievably strong.  ( and simple too!! ) I know the top of it is a nightmare. But not the rest of it.  
I started collecting them back in the 80's I got them unbelievably  cheap.  started paying $300 and quickly got them for $150 with transmissions attached. And got really fussy and still got them free!!  
I took some apart and in 35 engines I never found anything wrong. No ridge  in fact  a lot of them I could still see the honing marks from the factory.  Bearings nice,  rings good, valves rarely showed any real problems. 
 

In reply to golfduke :

The three cheap V12's are Jaguar, BMW, And Mercedes Benz.  Anything past 2000 is going to be expensive. In part because they came out with plug and play.  Plug in your tester and you don't really have to trouble shoot to identify the problem. That makes a lot of parts replacers  great mechanics. 
 

Jaguar got a terrible reputation well because they just looked scary.  Mechanics who really didn't know what they were doing talked a lot of owners into expensive rebuilds.  That or they neglected the basics. If you have a lot of leaves jammed between the radiator and the A/C  yes the car will overheat. 
or you neglect to do the required maintenance  because that's not what you normally do.  Yes the factory calls for oiling the distributor. 
What I really like is Jaguar started out with carbs. 4 great big simple side drafts. If you are as terrified of computers as I am you can retrofit. And Group 44 made over 500 horsepower on carbs. 
Luckily there is a 3 part series on UTube that makes the Fuel injection as simple as it really is. 
That plus Kirby Palm offers a free downloadable book on owning a Jaguar V12 without all the myths.  It offers simple ways to maintain them. 
I should let others talk about BMW and Benz  because I haven't spent much time with those brands.  I do know they use 3 ECU' s and it seems to me that some things in one change things in the others. 

BrianC72gt (Forum Supporter) said:

Do you still need to whack the fuel pump with a mallet to get it clicking away again?  I think they had some form of points in there on me old 72 MG BGT.  Reminiscing aside, I'd want to confirm fuel pump output, FP relay and pressure regulator .  And those are hoses you want to change BEFORE they start leaking.    This model is really growing on me.  Yours is too pretty to restomod.  Best of luck.

No the old whack the fuel pump trick was because the points were dirty.  Clean the points and the Old SU fuel pump is remarkably reliable ( and at the right pressure for SU carbs. ).  
But fuel injection is in the gas tank same as most fuel injection cars and pretty reliable actually. 

In reply to frenchyd :

There is a nice looking XJS imported from England for sale near me. Right hand drive. Corsworth Yellow , Has the 9.1-1 compression with the good head and no Catyltic converter.  Better advance 299 horsepower compared to 262 for American specs. 

A few years ago, I started looking at XJS'. Back then the prices were so cheap! I could always find 4-5 of them for sale for a couple grand, most of the time not running good, but still. I went to see one, the guy wanted 1200$. I was tempted, but back then I had no room for another car. Now that I could have the room, the prices have gone up. No more "projects" listed in the classifieds, and most of the ones for sale are the facelift convertibles. People want 20k$ for them.

OP you are lucky to have found one! I hope it treats you well for your hard work so far.

In reply to Rocambolesque :

Jaguar has always been a brilliantly engineered low volume car that suffered because of its low volume  

When Ford finally invested sufficient money in the company the reliability started to show exactly how brilliant the cars were. 
No less than Enzo Ferrari called Jaguar the most beautiful car ever made.  And it's 7 LeMans wins  verify its true competitive capability. 
In the early post war period those Jaguars were road driven from the factory to LeMans Raced and driven back to the factory following their wins. Or on to other race tracks  

Back in the 90's  and 2000's  V12 Jaguars were given to me  in part because they were damaged but also because they had such a poor resale value, it was like they were just disposing of them.  
 I'd pull the engine and maybe a few other bits. Then scrapped the rest. Some great fantastic cars wound up trashed because they were only worth scrap metal prices. 
That all changed when Ford bought Jaguar and invested so much money in the company. Before that Jaguar went from independence to joining British Motor Holdings to independence to Gas shortage, to California Smog emissions, one step away from bankruptcy.  
PS if you are still looking for a cheap project car let me know. I'm always stumbling on them or people call me up looking for a home for a project they gave up on.  

Glad to see you moving on from engine work.  Make sure you oil the dizzy or rebuild it just as posted above!  I forgot that part.

Now that you're on brakes, do you have inboards or outboards out back?  If you have inboards......have fun.  My discs were good, thank God, but I had one bad caliper and needed pads.  I just got the car up as high as possible, bundled up (in my driveway in February) and settled in for a LOOOOOOOONG day, 1/100th of a wrench turn at a time.  In the end it wasn't that bad but I went into it with a good attitude.

If you're lucky your discs still have the access hole in them.  There was a cutoff year, and most aftermarket discs didn't have them either.  Mine did.

They're inboard rears. The change was '92 or '93. The access holes depend on the diff, Dana got access holes and Salisbury didn't. I haven't actually measured the rear disks yet, but I'm planning on replacing them. The fronts were in need of replacement, but the car came with a pair of new rear disks in the trunk, so I assume they needed to be replaced a while ago. I've got a four day weekend coming up, and the weather is supposed to be nice. I hope to finish up the front and head to the rear. I've pretty much resigned myself to the fact that the axle needs to come out...

The distributor is free, it springs back easily and smoothly. 

Darel said:

Glad to see you moving on from engine work.  Make sure you oil the dizzy or rebuild it just as posted above!  I forgot that part.

Now that you're on brakes, do you have inboards or outboards out back?  If you have inboards......have fun.  My discs were good, thank God, but I had one bad caliper and needed pads.  I just got the car up as high as possible, bundled up (in my driveway in February) and settled in for a LOOOOOOOONG day, 1/100th of a wrench turn at a time.  In the end it wasn't that bad but I went into it with a good attitude.

If you're lucky your discs still have the access hole in them.  There was a cutoff year, and most aftermarket discs didn't have them either.  Mine did.

It's scary how fast you can pull the rear end of a Jaguar out.  Anybody doing work on the brakes needs to drop the whole rear end. 
On a hoist  it was 40 minutes or less depending on how badly rusted things were.  And 30 to reinstall.  Once  out of the car it's less than an hour to have it totally disassembled ready for cleaning and paint. 
What really surprised me was how few of the really rusty bolts broke.  The hardest part was separating the drag links.  In fact so many of the cars had totally rotted floors and one good slam with a sledge hammer broke everything loose. 
   The whole movement of the rear end was on needle bearings. But because the arc is so small only two or at most three took the whole load.  The result was even on well greased assembly's two or three of the needle bearings would flat spot.  
I totally eliminated that assembly and replaced it with a grease-able bushing I turned on a cheap worn out lathe I had. Brass at first and finally just used aluminum.  Doing that  I saved them $2-300. The result was slightly more steady cornering and less rear wheel steering going over Railroad tracks at an angle. To be honest not one person in a 100 ever said anything except that it seemed better to them. 

In reply to garethashenden :

Work in progress on my XKE V12 race car.