Distributor cap and rotor

I’m a bit confused as to what cap and rotor to buy for my HE 88 xjs. I know it needs the vents. I see black caps with Lucas stamped on them, but I also see blue caps that claim to be Lucas. I also see aftermarket black caps, which I want to avoid. My current cap is blue. And how do you determine a rotor is OEM Lucas? Thanks.

Original Lucas cap was on my 1987 and now has Blue distributor cap as shown in attached picture. One bit of caution is to carefully compare replacement rotor of the original for height. Once did not and the replacement had a back side weight that hit the flash shield and made a mess of it. Had to replace flash shield. In the attached picture you will notice that a small piece of lock wire has ben used to keep the vent tube from falling down under the cap… Also used a very small amount of epoxy to seal it. Not necessary but makes replacing the vent hoses easier.

Greg, if you want an OE cap, do a search for DAC 4168. There is one on e-bay right now.

Greg,
The part number for the OEM distributor cap is DAC4168 and the rotor is JLM9624.

I often purchase parts for my Jaguar from the local Jaguar dealership parts department. The offer a generous discount to Jaguar Clubs of North America (JCNA) members and they don’t charge a shipping or handling fee as long as I pick up the parts from them.

I know that purchasing parts directly from the dealership doesn’t work for everyone, but I have found their prices competitive, and I know that I am getting the right part for my Jaguars. They certainly don’t carry everything, but I have been pleasantly surprised by the wide range of parts the dealership can get for my wife’s 1990 XJ-S convertible and my 1990 V12 Vanden Plas.

Paul

My experience is that all new caps with Jaguar labeling are made by Jaguar’s “suppler of the month” and are of poor quality. Most irritating are vent attachment nipples, which soon loosen and tend to push inside the cap when you try to push the hose on. Mine are now bonded with JB Weld. This lasts awhile but is not a permanent fix because nothing sticks well to Nylon.

Also, be sure to deburr the posts and thoroughly clean the cap inside, as I’ve seen aluminum chips left over from the machining.

And finally, those posts shouldn’t be made of aluminum in the first place. The reason is the plug wire tips are steel, and are no longer rolled at the end, so instead of snapping neatly into place the tend to gouge into the aluminum.

My long used and trusted Jag parts supplier, Exotic Car Parts, can only apologize, saying that’s what we get from Jaguar theses days.

So I’m still confused, if I order an OEM part from dealer, do I get a black one with LUCAS on it, or a blue one without LUCAS on it?

Oh and thanks for all the help. Part #s, as well as dealing with the vent caps.

Greg,
I believe that you will have to call you local Jaguar dealership parts department to find out if they have the black Lucas cap or the blue one.

My wife’s XJ-S convertible has the Marelli ignition system and years ago when I was looking for a spare OEM Marelli distributor cap the dealership had run out of the OEM caps with “Marelli” cast into the plastic and only had the aftermarket ones with “Made in Italy” cast into the plastic. They were selling it with the same part number. At tge time I was lucky to find a NOS OEM Marelli cap and rotor elsewhere.

I’d say your first step is to call the dealership parts department and find out what they carry.

Paul

Is one better than the other?

Almost certainly blue. It won’t say Lucas though. Apparently, even though Lucas no longer exists, Jaguar can’t legally use the name without paying someone a royalty.

I haven’t seen a new black one in years. IMHO, even if someone is making a black one that says Lucas it will of the same quality, or lack thereof in this case.

Lucas still exists…but not quite as we remember it.

Lucas sold-off its automotive division back in the mid/late 90s. The new company (name escapes me) still sells lots of “Lucas” branded parts. I’m not sure if they do their own manufacturing or if they’re just label engineers…or perhaps a bit of both. When I bought “Lucas” coils for my XJR they were made somewhere in eastern Europe with “Lucas” stamped in yellow ink…and were lousy quality. The true OEM Lucas coils were made in Japan by Diamond Manufacturing. Hard to know what you’re really buying these days.

As for V12 dist caps, FWIW, I’ve have no problems with either of my V12s using the blue caps that come in Lucas. boxes.

Cheers
DD

When did you last get one? If fitted with vent nipples, are they still tight? Can’t believe I’m the only one having experienced this.

Within the last couple years.

The cap works fine in terms of delivering sparks.

I glued the nipples in place before installation just on GP. I thought this was S.O.P. ! :slight_smile:

Cheers
DD

I’ve been waiting for someone to find a nylon bolt/nut combo that can be drilled and the end machined smooth to replace those POS fittings that just fall out.

Curious, if the nylon nipples fall out easily, can’t we just replace them with plastic equivalent, and then epoxy the joint?

Complaining the nipple falls out is like saying the wheel falls off if you don’t replace the nuts. I.e. you only use half of the stud/nut fastening pair so what do you expect???.

The nipple is held in place by the hose and clamp. No hose and clamp, no nipple security. The hose should be fastened to the nipple pushed into it from inside before the cap is fitted. Depending on grade of hose material, it should last the life of the car and/or several caps, whichever is the longer. It only needs disturbing when changing caps, so needing internal access isn’t an issue because you’re replacing the cap anyhow. No extra work is involved and no glue needed and the nipple never moves. I assume the cap material needs lots of filler to ensure high tension insulation and that requirement makes it too brittle for thin wall spigots to suit small bore hose. Metal nipples are out, so they used a tough nylon type of material ideal for the purpose.

Never thought of doing that, Peter. I’ll give it a try. However, I still think the current part is inferior. The OE caps that came with nipples did not loosen. As I recall, there was a nylon ring serving as the “nut.” There was no hose clamp.

BTW, the last time I had to go in for a smog check I took the car to a shop for changing the plugs, and to fit new ignition wires. When I got it back the wires were not properly seated in the cap due to the steel tips gouging into the aluminum. Also, the side vent nipple had been pushed into the cap. The tech was relatively new to Jags, having recently taken over a Jag shop when the owner passed away. He is a competent young man with lots of auto repair experience and has worked in the Jag shop for about 5 years and ought to be able to do this job, but failed due in no small part to crummy parts. IMHO, of course.

Wow, you still have to take your XJS in for a smog check? Here in WA state, once a car is 25 years old, it’s exempt.

I’m sure there are generic parts for any car that sold more than a few hundred, and even those typically used lots of parts mass produced for other models. I clearly haven’t seen every make of cap Ed (my current V12 has an orange one) but the same principle applies if the hose nipple(s) are floating in the cap with a shoulder rim to stop pull-through.

It’s all speculation on my part, of course but WYSIWYG suggests I may be in the ballpark

No, it’s not. The nipple has an inner part and an outer part. The hose clamps to the outer part, which then falls off, allowing the inner part to drop inside the distributor.

You could ditch the outer part and clamp the hose directly to the inner part, but you’d have to change to smaller vent hoses.

In thecase of the two part nipple which will not glue well because it is nylon…you could melt the top edges together with a soldering gun…best done before cap is installed and trim up with exacto knife and then put hose on anytime…you can put a small hook inside temporarily and hold the inner nipple up…so it won’t slide down while you do the “weld”…a helper will be needed…it is too bad that the inner nipple was not threaded so a nylon lock nut could hold it…hmmm…