I just tested it with two extra washers under those rubber grommets, spaced the trigger board probably ~0.050" higher off the reluctor, and the car started right up! One of the reed switches was still sticking open though and it sounded like it was running off six cylinders - that could either be a sign that the board itself is borked or that it’s still a bit close to the reluctor.
For the hall effect board, I found a used one on ebay. I’ll try that one with new grommets later and see how it does.
Is the reOpus even available anymore? I searched for a long time and saw that he’s not making them anymore. The only options I saw were getting a CEI ignition system, the Pertronix, or Crane.
Confirmed all twelve cylinders work now with the new hall effect trigger board. I didn’t bother trying again with the old reed board, so I can’t say for sure if the old spacing+washers was enough, or if the board itself was just bad; it was going to go bad sooner or later anyways.
I ended up getting 3/8" long silicon spacers at the hardware store and put a washer under the rotor so it doesn’t collide with the trigger board. The spacers may not even have to be that long, but everything still fit under the distributor cap and the car runs so it’s all good. If it didn’t fit, I’d just shorten the spacers until it did.
So if anybody reading this in the future wants to replace their OPUS ignition with the Pertronix, it works, just be mindful of magnetic interference and the gap between the reluctor and trigger board. Fresh rubber grommets look like they work - old squished ones do not.
I did buy mine YEARS ago when they were made by someone in particular, whose name escapes me. The newer versions are not branded ReOpus and are not made by the same person. One big difference is you no longer have to give SNG your old distributor, they are not using old cores in the new distributors. Plus they cost much more than they did when I fitted one to my XJ12C!
I have a strong suspicion that the ReOpus was designed by a guy here in NZ, just digging a memory up from maybe 20+ years ago, if so he wasn’t young then.
Yay, my OPUS ignition failed me last night on my 1976 Pre-HE XJS V12. I’m going to convert it over to the Pertronix system as per this thread. Any updates on this thread since Nov "22?
I’m going to re-read through this thread multiple times to try and get a complete understanding on the modification and install. Thanks for writing this thread! Wish me luck, Tom H
My system still works fine. I don’t run the car all that often, however.
Be sure to lubricate the advance while you’re in there.
Take pictures as you disassemble, though it’s not that intricate. It’s pretty straightforward when you’re looking at it.
FYI, the best thing I’ve ever done with this car has turned out to be replacing the catalytic converters. If you’ve never serviced them, I’d consider a service of some sort. Mine were totally melted down.
Also-
If you search ebay, you can sometimes find a NOS rotor- here’s the search term I used:
Lucas Rotor Arm for Jaguar / Daimler Part No. 54422422 / RA15 (double check for your model year, likely the same)
I managed to find a NOS rotor and a new manufacture cap from moss motors. I did it a year after the pertronix, but as they say “while you’re in there”
Zack,
You are awesome!! Thanks for taking the time to write up how you converted the OPUS system to Pertronix. I installed the Pertronix unit, with the offset you suggested, and it started up with no problems. The timing was dead on @10 degrees and was rock steady. The car idles much smoother and has power all the way to the redline. It would cut out around 4000 rpm before the conversion. I used the resistor for the tach and works like OEM. Thank you again, Tom H
Hey everyone, just wanted to update with my experience with the Pertronix on my 76 XJS since installing it.
I had previously stated that I got it working when I spaced the trigger board further from the reluctor. That did work, to an extent. The car would start, but I soon found out later that when doing my test drives, it would not be able to accelerate at all and within the span of 3-5 minutes would start to bog down more and more until it would just die and wouldn’t start again until some time later. It never felt like it revved right and just seemed extremely rich.
I had gone through EVERYTHING I could find. It was getting healthy spark, my timing was set, my fuel system was healthy and would sit at 30psi solid.
My guess was I was still getting electromagnetic interference between the reluctor and the trigger board and I could not solve the problem. I even tried shielding the reluctor with faraday cloth tape and it just made the symptoms WEIRDER. I contacted Pertronix and they said the interaction of magnetic fields will absolutely affect the system and can even damage the pickup.
I’m not sure why I seem to have these problems but multiple people here are running it without issues.
Hey Zack, my car actually doesn’t have cats at all on it. I would think we had the same kind of distributor because we both have the reed trigger board, I don’t think they changed any of the dimensions. I spaced the trigger board as far as I could from the reluctor, to the point where I nearly ran out of room for the rotor above.
The car would get worse and worse within the minutes it started. It was running RICH, and it felt like it just kept getting more and more rich, like it was flooding until it died.
Right now I have a Crane system just installed, so far it runs without any of those weird symptoms. Starts and idles completely normal, revs strong, drives well so far. Will do more testing in the future to make sure that I don’t have the same symptoms as when I had the Pertronix.
No idea what was truly happening. I could potentially hook up my oscilloscope to the injector amplifier leads and watch the pulses as the engine cranked, to see if it was steady or if there were any weird anomalies that could’ve been from the electromagnetic interference. Maybe for a future experiment, because man, I have been exhausted chasing all of these symptoms.
Well, I guess that eliminates exhaust blockages.
My thought was that someone could have swapped distributors on one of our cars for some strange reason before we ever had them as there are a couple versions from what I can tell.
That does seem less likely if the crane is running on yours.
Side note- the rotor also has a ferrite core on the back end. Perhaps that core is also triggering the Pertronix and firing off ignition a the wrong time, leading to un-burnt fuel and loss of power.
(or several things are happening)
I’m not sure what else it could be than jaguar’s less than perfect manufacturing tolerances (or Pertronix)
I agree it sounds like an EMR issue. Personally, I’d just keep the crane on until you needed otherwise; Chasing these things is brutal after a while.
Sounds like it’s happening when hot, could make troubleshooting with a scope more interesting.
You wouldn’t happen to be located anywhere near NJ / NYC, would you? You’re more than welcome to see my setup.