THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

As a concluding comment here, I have swapped the cap, rotor, and wires out for a slightly newer model set up with push on ends on the plug wires at the distributor. I ordered the parts from Rock Auto referencing a 1972 xj6 4.2 as a more or less random choice. All fit well with no adaptations needed (this was my original concern). I feel better about the contacts but the problem remains. The saga continues.....
Thank you all for your input!

Yes. The split washer acts as a slight spring washer & keeps everything tight.

Ah! I see the washer with the strands. That seems much more secure as the nut would then have something to hold. Since mine do not, I have put a wrap of electrical tape around the end of the wire to increase its circumference. This only "sort of" works.

This is the genuine Jaguar HT lead set I have fitted to my car but fitted with Champion bowtie plug caps which screw into the leads. Supplied with the set.


This is the correct termination for the leads with Acorn nuts & split brass washers. I have no issues at all.

I'm trying to deal with a 2 or 3 fold problem. One is that the wires pull out of the cap very easily making me wonder if they Ever make a good contact. This thought is compounded by (two) a high speed low load miss which feels a lot like hitting a pothole. And 3, some of the wires have brass contact plates at the dist. end and others have small screws directly into the end of the wire. I suppose either way could be sufficient, but the whole thing just seems so .... tenuous. I do not have the conduit to thread the wires through. It's the contacts in the cap that I don't trust.
I have not dealt with this yet as I have only just plugged (hopefully) all the Major leaks making the car Much more useable. Now I am moving on to "fine tuning the fire out." It's a win I suppose......

I changed to the push in cap and leads when I changed to electronic ignition. My leads are silicone not copper so I don't think the Acorn screw in caps would work with them anyway. My leads came as a set already cut to the correct lengths and had the spark and dizzy caps pre fitted. Only draw back is you cannot use the original HT lead conduit tidy that bolts to the cam cover because the ends of the HT leads having had the caps pre fitted do not fit through the conduit.

I'm still using a new acorn nut cap. No issues. Very late caps were push in side entry like the 240 & 340.

Never had any particular problem with the acorn nut dizzy cap but rotors in the last 10 years were a issue until I learned of the higher quality red one. If you still have the fiber conduit in the middle of the head, threading the HT wires into it can be a challenge. Try coating the wires with WD40 first, they'll slide in easier.

Hi all,
I was tinkering today and have come to the conclusion that I REALLY dont trust the stock distributor cap with the acorn nuts. I recall reading somewhere that I could swap in the slightly newer cap which has push-in terminals but looks the same otherwise. I need to replace the plug wires anyway so, while I'm at it I want to try the swap. My question then is this- Did I actually read that somewhere or was it simply a fanciful dream?