New to the forum, looking for some advice. My story goes something like this:

I'm out driving around tonight and the car is running fine. I get to a stop light...it turns green... I hit the gas and I have no power. It sounded bogged down, and I go easy on her and get her to maybe 30 mph so I can coast not the nearest parking lot.

When I park it I hit the gas a few times and she sounds not so good. That's when I notice what seems like an electrical smell. I shut her down and pop the hood. There's white smoke coming from near the dash slightly to the passengers side. I couldn't see very well as it was dark. I didn't attempt to drive her off and I'm pretty sure I don't want to crank her back up for fear she'll catch on fire...lol

Thoughts?

 

try unplugging the vacuum line to the ECU. The ECU will usually default to a "limp home" fuel table. might give you enough power to get home..... wish i wouldve thought of that when i was stuck in southern WV.

 

I'm not sure when they stopped using the Marelli ignition system, but if that is what you have in your car, it sounds like you burned through the rotor inside the distributor cap. It will shut down one side of the engine and continuing to drive is a great risk of fire.

To be safe, have it hauled on a flatbed!

 

+1 for marelli failure of some sort. DON'T DRIVE IT !

Even though I considered myself as informed on this failure after reading lots of posts on here, I didn't recognize it when it happened... car just felt underpowered and didn't want to go. I drove 2 miles home and the cat, steering rack boot and chassis leg were well alight by the time I stopped. Luckily I have fire extinguishers everywhere and I got it out without burning my house down. On reflection, I think the disconnect between my understanding and reality is that I was expecting the failure to feel like the car was misfiring....... whereas in reality, the V12 is actually configured as 2 separate 6 cylinder engines, so when one side dies the other side still runs smoothly. I won't mistake it the next time, although after replacing the entire ignition system I hope there isn't a next time in the near future.

 

first thing i bought was my Jag. the second thing i bought was a Fire Extinguisher. i keep it in the floor board on the passenger side, bolted underneath the seat lip. its a good look with the racing seats.

 

Thanks for the info guys. I had the flatbed come and get her. I pulled the distributor cap and it looks alright... maybe one tiny crack in there but I'm not even sure it's a crack. The rotor looks alright too. I did see that the wires are Lucas and the distributor cap was "Made in Italy", but it didn't have anything else on it.

I think I'll go ahead and replace them along with plugs and wires anyway. Given the smoke and the electrical smell I should be seeing something burned...but nothing. Coils maybe?

What else should I be looking at?

 

According to the wiring diagram, the '94 V12 is definitely Marelli ignition. On my car I had already replaced the distributor cap and rotor when I first got it as part of a general tune up. It was in fact one of my coils that failed. You have the rotor, the cap, the coils and the power modules (The black boxy things that sit on the top of the radiator mount) which are all "per bank" so a failure in any one of them causes the half engine issue.

If your garage reports its the coil or the power module thats failed on one bank, I would strongly recommend replacing that part on the other bank at the same time.

Your next problem may be that you've melted the internals of the cat on whichever side of the engine that failed, but let's get the car running again first....

 

You're correct. Definitely Marelli...but a replacement cap. Looks like poor Betsy has had this issue before. Strange since she only had 50k on the clock when I bought her.

I think I'm going to go ahead and replace the cap rotor and coils since who knows when and what got replaced.

I have been reading the bad things about the replacement parts and.... Does anyone have a recommendation on which brand to buy or a preferred website you guys get parts from?

Again, thanks for the help.

 

There are a lot of quirks about the cap..... some Marelli caps didn't have Marelli on them, some non-Marelli copies did, etc. I would buy from a reputable merchant that has been used before on this board, ie NalleyJagParts.

I bought my coils from my local Jaguar dealer. I think they were about $150 each

I got an email flyer recently from Welsh Enterprises who had the caps for $90 and the coils for $30. I've bought stuff from Welsh before and it was fine, but I don't have personal experience on their coils and caps

 

Well, I've been on vacation for the last week and just came home and took the rotor out. Burned... Albeit a very small portion. I mean it's one line of the "asterisk" described in Kirbys book. I assume this is enough to cause this whole disaster?

Crazy. Especially knowing these are replacement parts in there and she is still under 60k. Anyway, I figure while I'm looking at it I'll go ahead and change out everything while she's not running.... That way I can rationalize it as having done it for fun.

Thanks again everyone for the help and for contributing to this board in general. I've learned a lot reading all of this combined knowledge.

 

just a thought. if one half of you engine was dead and you were worried about fire..... unplug the injectors on that bank.

 

I've seen various sensor systems designed at home by people who wanted to be able to detect a marelli failure. I think there are some references in "The book" also. Some just gave a warning light on the dash. Others offered the ability to "do something", ie shut the car down, or disable the fuel injectors on the offending bank, as M90 suggested. I looked at them when I had my failure, but in reality, once it's happened to you once, you'll know the second time (I hope !)

 

Yeah, I had read some stuff about it because the car had an intermittent slight miss I was trying to diagnose. But yeah... When it happens... There is no doubt something is bad wrong. I was thinking "holy **** here we go....".

What I am wondering is if my car has had a cap and rotor replacement at least once already is there something causing it to occur more rapidly? Like I said I'm going to replace the cap, rotor, coils, plugs, and wires while I'm in there. Hopefully this will take care of it. This weekend seems like a good time if the wife doesn't have me getting the baby's room ready...sheesh. . She'll never understand how important Betsy is....LoL

 

One more thing I thought you guys might get a kick out of. The car is nearly dead and I'm coasting into the local Target parking lot. I'm semi freaking out and thinking about repair bills. Just then I hear some kids on the sidewalk talking about how awesome the car is and how they want one when they grow up. Such is the allure of the XJS. I made sure to coast out of sight. I didn't want to prove their parents right and discourage a future Jaguar owner.

 

Some of the aftermarket caps and rotors were substandard. My cap is quite heavy and is about 2-3mm thick. Download KP's book there is a writup in there on modifying the rotor with silicone that apparently prevents this happening again

 

Just thought I'd mention the cap and rotor replacement did the trick. I went OEM from Rock auto. She still has a miss from time to time so I'm going to go on with the plugs and wires, etc. I also noticed she's running a little hot so here we go with that... But it's all in good fun. She gets a second look everywhere she goes.

 

Glad to hear it!

 

if youve got an occasional miss, i would tinker with the ignition timing just a tad and see if its just a little bit of knock.

youre cat on that bank might not be in great shape so i woudl check on that also.