Ok
I’m not sure it’s so much a bypass as it is a replacement out side of the ballast with an in-line resistor.
I am fairly inept at pasting and etc.
I will give it a try.
If anyone wants to walk me thru it I’m game.
Mark Bailey
Tomaytoe, tomahtoe. You’ve gotta make it clear to the nimnuls doing their own repairs that you’re taking the resistor pack out of the circuit, just in case it’s bad. So you use the word “bypass”. Then you add the inline resistor to provide the same protection.
Just snap a photo of those Lucas instructions. You can then attach the photo to a post here with that “upload” icon at the top of the edit box.
OK, it seems to me that the diagram in this photo and the diagram of the resistor pack above don’t jibe. It’s been 20 years, I dunno how I assembled the info for that resistor pack, but it simply doesn’t make any sense that the ballast resistor connected to the + terminal of the coil would be in any way connected to the tach lead which is connected to the - terminal of the coil. Does anyone have any better info on the internal connections in the 9BR resistor pack?
Was there any issue with ‘phasing’? I have seen Crane write-ups (B Embden or Ed Sowell?) that said that there was fiddle and checking that on max advance that the rotor didn’t discharge to the neighbouring HT terminal
I reckon the 1121 fits the later reluctor type distributor- looks like the aluminium pertronix plate fits over the studs/screws that hold the original sensor
You’re saying that they had an issue with the coil not discharging when the vacuum advance was at 100% (or close to it) because the pickup didn’t stay in line with the disc?
Seems it could happen with either. The crane, an optical system may be more sensitive to that than the Pertronix as it’s magnetic.
I haven’t seen that happen yet.
Oh, yeah- that could be it the screws seem to match. I haven’t seen the inside of one of those before. Makes sense looking at it.
I’d cross reference the “fit” from the manufacturer with other models using the same or similar distributors. It worked out for me but I wonder if the EFI board would be an issue here?
I suspect this is happening to me.
I have an xj12 on carbs- new to me. It has been well gone over by a marque specialist- who identified and replaced a dud vacuum retard unit. The car has a crane xr700.
I haven’t really had a good look at the crane installation, but have had an issue with very brief ignition failure when under a bit of load. Example is increasing throttle when starting to climb a hill at 70mph. There is less than a second cut, the tach drops, no ignition warning light. Other times, all is beautiful.
I suspect that as the vacuum retard is released, that some evil befalls the pickup or its wiring
I have read with trepidation the crane installs from Ed Sowell etc and it sounds as if the whole concept of mounting the sensor is flaky.
On other (non jag) cars ive had good results with pertronix
Hello Zack
I have a DD6 2door, the ignition still works with the 2nd amplifier I had bought more than 30 years ago. I love Pertronix, because It runs perfectly with the V12 E-Type, so I have always wanted to have it in the V12 EFI as well, which “is not possible”. Now you have come to the rescue, and I would love to have it as well, with an updated trigger plate of course, because I am thinking of the billions of open/close of the reed contacts.
Nevertheless there is one point, that you have not addressed, maybe because it is not a problem, and its just me:
When I look at the picture, I see the pickup is not fare from the trigger board.
When there is vacuum, the pickup moves slightly clockwise, upwards in your last picture.
Did you check, that even with full advance, the pickup does just not touch the plate?
Maybe you have checked it already like a guy in You Tube, with the distributor open and vacuum applied externally.
I thank you for your simple but ingenious solution and would like to hear, if your V12 is running well, and that the slightly loose black Pertronix plastic part is definitely not a problem.
Regards André
I have just found the data for our distributor:
Bosch Lucas EFI, 9:1 compression, 1975-80.
750 r.p.m. (static) 10 degrees BTDC
3000 r.p.m. 29 degrees BTDC
So the pickup moves another 19 degrees clockwise, and it could be tight.
André
Hi André,
Frankly, It’s been a couple years and I’m not sure I completely remember. I sure would like to think this was checked. If I do recall correctly, it came VERY close
When I got the car, it hadn’t run in close to 20 years, so I was never able to experience it “from factory” to compare.
I do need to get back under the hood in the next few months, I’ll check it out.
Zack
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Andre- that timing data sounds like crankshaft angle rather than distributor (which is of course half the crank values)
Thank you Russel, you are right, it is just half the angle, but according to Zack, still very close to the trigger board. I have yet to decide which ignition to choose:
- Pertronix
- Ignition conversion kit DAB113HEF, where they use the HE distributor. The ignition module is in the old Opus box, so it looks original.
I would prefer Pertronix
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Oh, Look at that, Just barely clears.
Hi André,
I was finally able to get in there and it does in fact clear on mine, by a hair.
Another thought-
I was able to find some rotors with the EFI trigger on ebay, it seems like they’ve been discontinued for some time but they seem to come up new old stock sometimes.
I suggest stocking up if you can!
Daimler Part No. 54422422 / RA15
Hey everyone, I made a new account just for this thread because I just installed the same Pertronix system in my 76 XJS following the procedure in this thread. Spark works perfectly now, timed and everything.
However, my reed trigger board is acting up because the Pertronix reluctor is magnetic. Out of the distributor it closes the switches just fine with a magnet, and before installing the Pertronix it was running completely fine (until the ignition amplifier died of course).
When I crank the starter with the board and rotor in both switches in the trigger board immediately close and stay closed, which prevents the injectors from firing.
I’ve checked pretty much everything else on the car. Fuel pressure is solid, injectors engage when I turn the throttle switch, I can start and idle the car on just the cold start injectors. I bought a hall effect board and rotor but the switches don’t seem to be working and I’m diagnosing that right now.
Have you guys run into problems with the magnetic field?
Hey Don,
I haven’t had any issues with that. I was initially concerned but it never turned out to be justified for me.
Can I ask a few questions?
You’re using the black Pertronix reluctor wheel, right?
Do you have the original trigger board or a new one?
What PN rotor are you using? Does it look like the one I have in the picture?
Is the wave washer installed below the rotor?
Are you using the trigger board mounting kit or something that approximates it?
Here’s what Mine looks like all installed (I have changed the rotor for an exact fit since)
Note the SS screws with the rubber grommets. I sourced these from a local hardware store when the nylons were all broken. (the nylons are probably better though)
I’m wondering if the issue you have is the distance between the reluctor and the bottom of the trigger board. Perhaps a manufacturing deviation could be enough to bring them too close. Or maybe the old rubber on the mounts is too compressed?
I’d start by checking those mounts.
Zack
Thanks Zack. Yep, using the new Pertronix black reluctor wheel.
I have mainly tried it with the old 3 wire reed switch trigger board (with the original old rotor like yours). I have also tried it with the new hall effect board with its new rotor, but that one doesn’t seem to be reading correctly in my tests and I’m still figuring it out.
It’s all installed with the wave washer under the rotor and the original rubber grommets. I actually had the same thought as you when I woke up this morning - the distance from the reluctor to the trigger board might be too close due to the rubber getting old and compressed. I’ll try some tests this morning with the trigger board spaced differently and see if I still get magnetic interference.