I am looking to purchase a 1990 Jaguar XJS and I have a couple of questions for the XJS gurus out there.
What years XJS carry the same bonnet as the 1990. The seller has a bonnet from a 1995 XJS. Will that fit the 1990?
The car has the Marelli ignition system. Can it be converted to the Lucas style ignition system?
The PO sent me invoices for over $8K that was spent on the car before he said the engine "BLEW UP" What that means I do not know. I am still to ask him whether it was a cooling issue or a mechanical one.
Looking at the invoices he spent over 7grand including labor on the cooling system just before he said the engine "BLEW UP" so I am leaning towards that. The engine turns over so that's a plus. I am going to see the car next Wednesday and make a decision then.
Thanks.

 

I think so.

Surely the Marelli equipment can be abandoned. I'm 99% sure a Lucas distributor will drop right into place. Wiring mods to accommodate the Lucas system should be simple enough.

What I'm not sure about is this: The Marelli cars used a different fuel injection ECU. Some research would be required on swapping-in an ECU for a Lucas car.

All that being said....

The prospect of owning a Marelli car should be less worrisome now than it was years ago. We know how to maintain the Marelli system; we know what to watch for.


It would be interesting to see the invoices.

At retail parts and labor rates that $8000 might not actually be all that much work.

What's potentially worrying is that a shop not familiar with V12s may have quite unknowingly bollixed things up.

Cheers
DD

 

The facelift bonnet catches are different. I do not know if the old catches will fit, and the closing mechanism is different.
I hesitate to disagree with Doug, but I think that the fuel injection is the same and the Marelli parts only affect the ignition system. The Lucas ECU is still in Marelli cars and still runs the fuel side of things.
You will need an ECU that runs the Lucas ignition, as the Marelli cars' Lucas ECU one has that part disabled. I think!

 

These are some of the invoices I received. There is another invoice for 7 grand plus but I cannot transfer it from my phone to my laptop for whatever reason. This invoice is the for the cooling system.

 

Why do you want to convert from the Marelli system to the Lucas?

 

To clarify....

The Marelli cars have an ignition ECU and an fuel injection ECU. The fuel injection system on a Marelli ignition car is essentially the same as on a Lucas ignition car ...but the fuel injection ECUs carry a different part number for Lucas ignition versus Marelli ignition. The difference between the two is where the research would come in. I think the key (only?) difference between the two is the "trigger" from the ignition system to the fuel injection system; Pin 18 of the ECU. Two different types of trigger signal.

All of the fuel injection ECUs are labeled "Lucas"; it isn't an indicator of compatibility with one ignition type or another.

The Lucas ignition system does not have its own ECU. Lucas ignition cars have only a fuel injection ECU.

Cheers
DD

 

My feeble old eyes are struggling a bit with those invoices. A fair amount of non-engine-related stuff, tho.

We'll have to wait for a better explanation of "blew up", I guess.

The V12s are very robust. But there are a couple known failure modes. The "blew up" might refer to the dreaded dropped-valve-seats scenario. Or perhaps blown head gaskets. Bothe cooling system related.

Cheers
DD

 

IIRC, Roger Bywater stated that the Marelli system sends "cleaner" signals to the ECU which allowed modifications to the ECU to not have to do so much signal filtering work.

BTW, I wrote to Roger a couple of months back and never heard back, hopefully he's doing alright.

 

Also, I think the '95 hood would look out of place on the '90. It has the higher "bulge" down the middle, which looks fine with the other redesigned body panels of the facelift (keep in mind that every body panel was different on the facelift and the proportions modified).

 

I am not necessarily concerned about the Marelli Ignition. If it is functioning and in good order, I will leave it as it is.
The reason I asked about the 1995 Bonnet is because the seller told me that he had a '95 bonnet. I have a 1988 H&E convertible version and the hood is pretty much flat. How much higher is the bulge on the '95 bonnet? If it lines up with the body of the car, and the quad lamps in the front, I will be OK with that. The car is not for show but to drive. I will look for a picture on the internet an see the differences of t he bonnets. The other thing the seller has is another V12 engine. I do not know the condition of it at this time

 

Sanchez,

I think it's really important that you establish what has happened to the engine before you consider whether to buy the car.

Maybe "blew up" means something different on that side of the pond? To my mind, it would mean the engine has been destroyed, a conrod through the block etc.

As Doug has mentioned, it's almost impossible to read any of those invoices. However, after trying to interpret the words, it seems the only work on the cooling system relates to:

- Changing the 3 radiator hoses + one other pipe
- Changing the thermostats

Absolutely don't buy the car, until you know exactly what has happened. You could be looking at many thousands of $s for an engine rebuild or a replecement engine.

Good luck

Paul

 

Sanchez
If you look at any photo of a 6 cylinder pre facelift car, that has the same bulge in the bonnet (hood) as the facelifts. This had to be there to make room for the upright 6 cylinder engine, which is taller than the V12.
Ford rationaised the parts post-facelift by fitting the same bonnet to all models. I suspect the metal fit is identical, but it is not certain. Do not overlook the catches though, facelifts have a completely different system, both the latches on the firexwall, the catches on each side of the bonnet, and the closing lever inside.
Quite honestly, I think finding a pre facelift bonnet is a far better plan, there are loads about I am sure. Some photos of the pre facelift 6 cylinder cars




There is not a huge difference , but the bulge is very noticeable from the driver's seat, if you are used to the peerlessly lowline, Sir William Lyons-decreed, V12 hood!

 

Sanchez - If you want a fun project, this might be ideal. If you pay a shop for most of the work, this could be a nasty money pit, and a car in better condition might be a better bet.

If the engine turns over, can you have a compression test done? Is the engine the only issue? What's wrong with the original bonnet? Will the car need a repaint when the bonnet is replaced? What is interior like?

If it needs a lot of work "everywhere", this might be good fun, or not depending on what you want, but I'd take along hard look at everything it needs and make sure go in "eyes wide open".

HTH, Dave

 

I purchased my first XJ6 in the '80s and since then I have owned more than 15 Jaguars which I bought restored and sold. I have never ever paid a shop to do work on any of my cars.
This '90 XJS piqued my attention because (as per the seller) the interior and body is in very good condition. The seller buys and sells Jaguar XJS's for parts resale. He contacted me about this one and gave me the partial history he knows about the car. Excellent blue leather interior, all the woodwork was redone professionally and that the car was used everyday until the engine failure. What he meant by "BLOWN" engine is subject to interpretation. He sold the bonnet and the tail lamps but according to him the rest of the car is intact. It is he who told me that he has a bonnet from a '95 XJS ' He also told me that the engine turns over, so 'BLOWN' may mean something else to him and the previous owner. I have some XJS parts: tail lamps, chrome bumper pieces, grills chrome surrounds etc. Also, I am not afraid of the car with mechanical issues since my only cost will be for parts.

 

Reasonably certain the Marelli cars have a different ignition set up than the Lucas cars.
Lucas depends on the advance mechanisms in the distributor while no such system exists in the Marelli distributor.
Swapping distributors should be a problem but getting the Lucas ECU. To work in a Marelli car is going to be complex.
The only Easy button it’s buying the whole wiring system from the guy selling the MAXXECU. System.
If that were me I’d switch the whole ECU. To MEGASQUIRT. Totally eliminating the distributor and go to coil on plug ignition. Similar to what the 6.0 cars have.

 

Potential money pit if you are unable to do your own work. Repair shops,& Dealers have a labor rate and mark up rate significantly higher than ordinary cars. A brake job on an ordinary car with typically be 1/2 what the same job is on a Jaguar. Same with almost any task.
Regarding a blown up engine, Only a compression test will tell you what that means.

Removing cylinders heads can be an impossible task in some circumstances. It’s easy if the prior owner used distilled water and antifreeze and changed them every 2 years. If it’s been sitting a while with tap water in it. Corrosion on the 54 studs, even with the factory head lifting plate the best you can do is lift the head enough to saw the studs off. I promise you nobody wants that sort of agony.

 

Hi: a note about Marelli vs lucas ignition / engines: My 1986 car has a "marelli engine": it has the two sensors (flywheel and TDC) for the Marelli ignition. The engine was swapped by a previous owner and the orignal Lucas iginition is used. Works well, BUT the engine does not have a timing scale, so setting correct timing is not really possible.
Evert

 

Actually, it is possible. And when you do it you can make it a whole lot easier than the factory did. To set timing. ( they put it on the bottom of the damper ).
By hand rotating the crankshaft clock wise. Put the #1 A cylinder on Top dead center. I like to confirm it’s top dead center by looking at the camshafts. ( so yes, pull the valve covers off). Remember; Intake, compression, power, and exhaust. The 4 strokes of an engine in proper order. Now you can find exact TDC ( top dead center ) one of 2 ways. I have a dial indicator I use. But you can also hollow out a spark plug and put an adjustable stop rod in the center.
Go on UTube for a visual understanding of what I’m saying.
Without marks on the vibration damper make your own wherever you can put a pointer. Then mark your damper TDC. There is tape that properly marks off the degrees. It’s not permanent. So just use it to transfer those degree marks. I use a sharp chisel and tap a mark into the damper at each degree. Highlight each mark with red paint except TDC. Use white for that and make that the deepest mark.

 

@sanchez have you thought of calling the shop listed on the invoices? Maybe they can shed light on what is meant by "blown up" and may know significantly more than the current owner of the car's history and true condition.

 

I am going to see the car on Wednesday. Based on what I glean from the visit will determine whether I will purchase or not.
I will try to contact the shop that worked on the car to get some info.