Anyone know what this might be?
Fuel related? Crankcase ventilation? Found it lying not connected to anything. Car (V12) running fine without it. Bulkhead end of hose is connected to something.
Quentin

 

Filtered intake for distributor cap ventilation. Other end is connected to the cap.

 

Everyone asks what that is. It looks so weird! But that's how its supposed to be. The theory is that fumes can build up inside the distributor cap and then ignite causing the cap to crack. This was Jaguar's solution.

 

Thanks guys!
I inadvertently nudged it and then wondered if I had accidentally disconnected it.
The distributor cap needs venting....... who knew??

 

This was one of the first things "odd" I noticed when I first got my car.... I was unfamiliar with a vented distributor cap!! It sure as heck looked like something was badly the matter!!

 

A solution in search of a problem. I honestly never heard of any distributor cap caused fire or explosion.

Unneeded parts left out cost nothing and do not break.

Which reminds me, i need to get rid of that brake light bulb warning module.

Doug

 

There were a number of distributor small explosions which were thought to be caused by a build up of combustible gasses, which is why the system was installed. The exit from the dizzy is on the top and it is connected to the B bank inlet manifold via a rubber pipe:

 

Quote:

Unneeded parts left out cost nothing and do not break.

I've done a fair bit of culling myself.

But sometimes you have to be a bit selective.

FWIW, I'd leave the vent system in place. As mentioned, there have been cases of exploding caps.

Cheers
DD

 

Well, leave it to the Brits to make something that has never needed venting before, need a vent.

Dizzys in Chevs, Fords, Chryslers, AMCs, Kaisers, Hudsons, Deusenbergs, Cords, Ferraris, etc, etc don't have and never have had vented distributors, and don't have distributor explosions.

 

I guess that's the small price you pay for us "Brits" letting you have the privilege of driving a car with one of the most sublime V12 engines ever built! You're very welcome!

Paul

 

heh heh

You gotta get into the spirit of things with these cars. If you prefer typical/customary/traditional/common engineering features then an oldie Jag will continue to give you head-scratching (or worse!) moments

Remember, on an old XJS there are no design mistakes. Anything that appears to be a design mistake is simply an "interesting engineering feature" :-)

Cheers
DD

 

I would prefer a RR Merlin but will settle for the Jag V12.

Doug

 

Back in the 80s there was a TSB and a campaign for the vent.
The fuel injector hoses also leaked and I worked on MORE THAN ONE engine fire V 12 jaguars.

 

Ahhhhh....the joys of owning a classic Jaguar.