Your car appears to have a mix of pre-HE and HE components. An HE engine of that vintage would not have that distributor with the D-Jetronic components.
Is the trigger points module connected to anything?
Have you verified that the engine installed is actually an HE? You can verify from the engine serial number.

Jon

 

Yes, the situation is a bit confusing, I have quite useful documents for the XJS V12, but the XJ has deviated from it, especially in the late production years, and the documentation is poor. In any case, according to the parts catalog there was no trigger module in the 1992 5.3 V12 in the XJ.

I'll have to check how the module is connected in the next few days. I don't know if it's really an HE, I'll check the engine number one of these days.

Fritz

 

I worked a bit on the DD today. The cable harness from the trigger module leads towards the front and disappears under the ac compressor together with a cable from the thermosensor in another cable harness. It will probably go to the ECU, I would have to measure it. However, it is clear that different insulation was used for the trigger board than the other cables.
I couldn't identify the engine number, the back of the V is dirty and a bit oily, I would have had to dismantle a few things first.

For this I continued with the pick up module, when heated in the vice with the hot air gun, the signal on the oszi stays is missing at some point and the resistance of the coil increases from 4.0 KΩ to 1.1 MΩ. The module demonstrably fails when exposed to heat.

Fritz

 

Hi Fritz, I have attached the fault finding page from the workshop manual. The Lucas Constant Energy system is , in my opinion, a very simple and reliable set up, as stated by previous posters most problems are related to the Amplifier which in your case of no spark and at the same time would seem the case.
Regarding wiring the ecu signal wire (white wire that runs into a shielded cable) , this runs towards the rear of the engine into the ECU wiring loom. The only wiring that runs to the ECU loom through the front of the engine is the injector harness. Again good luck!

 

Hi Scd,

I agree that the CEI ignition would be the better alternative. Unfortunately, not long ago the owner paid a lot of money for the conversion with the DAB113HEF kit in his trusted workshop and it would be difficult to convince him to throw everything out again and convert it back to CEI.

I can reproduce the error on the ballast resistor and the pick up module on the workbench by heating it, see pictures and vid.

The resistor has a short circuit to ground and the pick-up module no longer sends a signal after a short period of heating.

I have now ordered a new distributor cap, distributor finger and pick up modul, and we already have the new ballast resistor.

I'm not happy with the hot position of the amplifier in the V, but I'm sure the Amp itself is OK.

Thanks, Fritz

 

As far as I know, the "ballast resistor" is simply a junction block. It's made to look like the original ballast resistor in a OPUS car, but functionally does nothing in a CEI car. You'll notice the warning sticker on it, indicating that it isn't functionally interchangeable with the part for an OPUS system.

I do hope the owner didn't replace the original distributor with that kit ( bit I'm afraid he probably did), as the advance curves are very different between a pre-HE and HE engine, the HE has much less advance than a pre-HE. I don't suppose there is any hope he retained the original parts? He could see the kit to an E Type owner, as it's completely incorrect for that engine.

As you correctly noted the amp really should not be in the V. That's why Jaguar moved it for the post 1980 cars.

The easy way to tell the difference between an HE and Pre HE is to look at the sparkplugs. A Pre HE are angled, HE is straight. I'll try and illustrate:

Pre HE plugs, looking from the side of the engine along one bank: / / / \ \ \ -> Front
HE: | | | | | |

 

Hi,
the ballast resistor is definitely not just a junction box, resistances from 0.5 Ohm to 9.9 KOhm are to be measured between the inputs and outputs.

The distributor is part of the kit and has been replaced, with most suppliers it is an interchangeable part. The original is no longer available.

We have to look at the ignition advance adjustment anyway, the mark should be at operating temperature of 18 degrees BTDC at 3000 rpm. If necessary, we have to replace the vacuum unit or flyweight.

Regarding the question HE or pre HE i understood your drawing, but it will take a few day til i get to the car next time.

Fritz

 

I have used one of these kits on a 1972 E Type, and when I opened up the box that goes in the V, the module inside is the same as the CEI cars, which is a General Motors 4 pin HEI module. The wiring diagram for that was given in post 5, perhaps what is in the ballast resistor box is the zener diode and the resistor for the tach feed?.

 

Yes, that can certainly be the case. The ballast resistor has two outputs, one forwards the pick-up signal to the ECU, the other leads to the ignition coil and the tach also receives its signal from there.
Fritz