With all the Marelli horror stories out there, I’ve developed a high level of fire-paranoia whenever I drive this gorgeous piece of machinery. My fire extinguisher and custom-made, hood-opener lie in the backseat ready for immediate use...Regardless, I still sense great anxiety

In reference to Kirby, I've decided on going with the exhaust-temp monitoring system as opposed to the custom, spark-fail indicator / led warning lamp setup as it covers a broader spectrum of potential problems, not just a tell-tale Marelli A-bank failure.

In addition, I also plan to incorporate two, manual fuel shut-off switches for each bank of cylinders so that in the event of a Marelli failure, I may be able to limp home on one bank without setting the car ablaze.

Are there any Marelli XJS owners out there who have experience with either of these (or other) precautionary measures? Any tips, suggestions, etc?

 

I don't have experience with those mods so I can't answer your question, sorry.

You didn't ask for my opinion but....well...here it is just the same :-)

I think you're going overboard. The only precaution needed, IMHO, is to pop the distributor cap every year or two and check on the condition of the rotor. It's the rotor, after all, that causes 95% of the Marelli melt downs.

Not that mine is the final word but I'm not aware of spontaneous Marelli rotor failures. The problem occurs over a period of time: wear on the contacts = increased resistance = more heat = melting and arcing.

Worn plugs or plug wires can add to the problem but new wires will last several years and, as far as plugs go, you can pull a couple once a year or so the check gap and condition.

Just my two cents. Hope you don't mind :-)

Cheers


DD

 

That's funny, ask Kirby where he got that idea. About four years ago IIRC.

Replace the coils, cap and rotor at 30K intervals (OEM parts only) and don't worry about it.

I have seen a number of failed coils which start the failure pattern, as well as cooked caps and rotors.

 

First off, I don't ever mind any of your commentary, Doug. Please do not hesitate to speak your mind at anytime!

My experience at trying to obtain OEM parts:

I bought a "Marelli" rotor and distributor cap and they were almost half the weight (yes, I weighed them) of the pieces that I pulled from underneath the rat’s nest. I cleaned those parts up, abraded the contacts, replaced them, and sent the new crap back (to Welsh Enterprises).

I have no problem wrenching and replacing this stuff, but where does one get quality OEM engine parts for this car? I have found that the online parts suppliers are fine for some things, but sub-standard for crucial parts like original Marelli ignition coils, rotors and caps, etc.

 

I just went through the same thing a few weeks ago. A bona-fode Marelli rotor is still available from Jaguar, under the Jaguar part number, but after quite a bit of searching and asking, I've concluded that the true Marelli cap is no longer in production. I used the Jaguar-boxed replacement which presumably (hopefully? maybe?) is still of decent quality.

Motorcars Ltd, Coventry West and all the other usual Jag suppliers should be able to get what you need but I usually ask what options they have for any given part....OEM from Jaguar, Brand-X aftermarket replacement, or known-brand aftermarket replacement.

For example, I'd be perfectly fine with Ducellier or Lucas labeled igntion coils. Brand-X...not so much.

There's plenty of the Brand-X stuff being sold out there and, in reality, most of it is probably OK....but I just feel better with brand name stuff, personally. Spicer u-joints, Lemforder ball joints, Timken or QH bearings, and so on. After some time you'll learn the goodies from the baddies.

Sometimes I find that actual Jaguar-labeled parts are very reasonably priced and are almost always high-grade. Of course, as we know, some Jaguar stuff is just crazy expensive.

As you're finding out, you just gotta shop around and do some research when buying your parts. Man, before the internet came along think how much more difficult it was, eh?

Cheers
DD

 

Having had a cat fire as a result of a coil failure on my Marelli XJS, I'm pretty confident it won't happen to me again..... simply because I now know what it feels like when you lose 1 bank. I knew immediately when it happened that "something" had went wrong as the car suddenly became severely underpowered and didn't want to accelerate. It did not feel like it was misfiring, which is because the 12 is set up like 2 independent 6 cylinder engines. I could also hear a "popping" noise (I have a convertible) which I'm pretty sure after the fact was the fuel exploding in the cat. I was STUPID and drove about 2 miles back home in this condition, which is what caused the fire. I managed to put the fire out with a fire extinguisher, and the fire was consuming the steering rack boot and the chassis leg underseal at quite an alarming rate, but a quick squirt and it went out easily.

I do all the preventive stuff with the cap and rotor, etc, and I do have 2 fire extinguishers in the car, but I think the most important safety feature is now my brain is super sensitive to any loss of power sensations from the engine. The simplist thing to do is just stop. I have AAA so they can just tow me back home and I can troubleshoot in my own time.

 

Doug is correct, the Marrelli cap is no longer available. I have about 7 Jaguar boxed caps on the shelf, opened them all, and not one is Marrelli.