So I've become very complacent having a good code reader to diagnose problems on my modern codes; no such luck with the old car. The 1972 XJ6 was running very rough a while back and I barely got it up the steep driveway. Later, pulled all plugs and no discernible clues. So I was looking around for vacuum leaks and while idling I got a good shock when touching the distributor. Found a crack between couple cylinders noticeable on the inside of the cap. Not a rigorous step-by-step process as I kinda stumbled on the alleged problem. Well I'll know for sure when I fit a new cap. Next up will be a new gasket set for the triple HD8 carbs.

 

Thank technology for NO codes on the REAL Jaguars.

That find is kind of normal diagnosis, move around until you get "belted", FOUND IT.

Same as "got spark, no got spark", get one of your MATES to hang onto a lead while you crank it, if they JUMP, got spark, MO jump = NO spark. Just dont grab one with a pacemaker, not clever.

Triple HD8's, that will be fun. Just ensure the main jet diaphragm of the front carby is in REAL GOOD condition, coz if that sucker leaks, and they do, it runs straight into the distributor, not good.

 

Cracks in the distributor cap. Seal them with miladies finger nail polish.

Run the engine at night with bonnett open. Light show???

Way back when Our famiy car was a Model A Ford. Cracked distributor caps was acertainty . Only an issue on wet mornings. Dad merely tied a bit of cloth to a stiff ire. dipped in the handy gas tank. Lit it with spark from an HT lead. a few passes on the cap and it was ready to go...

Alternate, ignite with his trusty Zippo lighter...

Carl

 

Installed new cap and spark plug wires. Purrs like a kitty now.

 

Once again, SIMPLE cars, only made complicated by over thinking.

Well done on the repair.