It would be great if the OP could link any further info or write up,
I notice he is an Aussie and an electronics tech
Are you in any Jag clubs ?
One of our Hunter Jag Club officials in an Electronics Engineer and he is brilliant with the later cars, he has a scope and all the gear, we have a lot of Jag dealer stuff etc
I have been put off several broken down S3, as no one can really fix them
30+ yrs old electronics benefit by upgrade
I will make some inquiry to him, but as an electronics technician myself, I can do harnesses and all the other stuff, but the more detailed information that is involved with such an installation is better
One can only ask and hope …anything is better than nothing
Great to hear that others are interested in this upgrade. I have started writing up my own experience and can certainly supply details of what parts I ordered, what brackets I made etc. It has transformed my S3 into a new car. Idle is close to perfect and it drives brilliantly. I’m in the process of installing a transmission sense which tells the Haltech when you select drive and helps smooth out the idle in transition. I’m also going to move the Haltech inside the car as it gets warmer than I thought it would by the servo. As we all know these cars run hot under the bonnet.
I’m based in Melbourne and yes I am an Electronics tech with 40 years in the game. I’m a member of the Jaguar Car Club but sadly have little time to participate. I’m not far off retiring so will definitely be able to then.
We have several vastly experienced engineers and technicians in our club, some retired
Our EE is running a technical day soon on “Modern Jaguars” I may head on up and chat to him about what he knows about S3 XJ electronics, almost certainly an immense amount, but possibly he is not familiar with the setup you are running
As I mentioned I turned down a lovely S3 V12 Saloon, been at the best (only) Jag mechanic in town for longtime, electronics kaput, was trying to sell it for what he owed the mechanic (for not fixing it)
A lot of guys would be grateful for anything you make available
Now that I know I have your attention, I may PM you some time in the future once I have discussed it with the other fellows
This is all great… hope you are not annoyed at me Pete for raising this old topic, but I really think it will be hugely appreciated once the details are laid out.
I know some of the purists wonder why I don’t just fix my L-Jetronic system. I agree it is a fine, reliable system when working, but my counter argument is that 38 year old cooked wires, inability to easily debug the black box ECU and lurking bad connectors (especially TO the ECU) are just super frustrating. I know a couple engine harnesses are available ($300-$600 USD) but I do not know of a “to the boot ECU” harness available, nor do I want to figure out how to replace that run.
So, in my case, I just sold my townhome for a tidy profit and have the great fortune to toss a few bucks toward my XJ6… hence my reasoning for kick starting this thread. Pete… I will still be putting together my own notes and thoughts about how to do this, but please let me know if you want me to “lie low” and let you just share your documentation. I am an electrical engineer with 40 years in the biz and about 20 in the car restoration hobby, so I have a rough idea how this will work.
Replacing that harness is easy! Just disassemble the interior of the car…
I look forward to your notes! It is precisely these kind of projects that will become ever increasingly important, to further generations, as these cars begin to get even older and more difficult to source parts for.
Also… I contacted Mobeck via their web site with full expectations of no answer, but Ole emailed me immediately and indicated the XJ6 version of his EFI system is imminent. He said he is building 2 systems for 2 clients but has not quite had to the time to fully announce it and add to the web site. I watched a great YouTube video about the XJ12 system, so have a feel of it’s implementation. I know the Haltech has extensive software setup support, but know nothing about the Mobeck.
Also his reply had a puzzling comment the the XJ6 system was “intended for carb engines”. I replied to ask him for clarification… do you think it means that his offering will convert a carb intake to an EFI intake. He cloased his reply saying he had no reason to believe his new offering would not work for an existing EFI setup.
Hi Gents, I certainly concur that the Jetronic system was fine in its day, but in my case 40 years later it becomes a real challenge to fix due to cooked wiring, oxidized connections, dry capacitors and worn-out components. In my case the ECU finally let go. Injector pulse width shrunk as the car got hot to the point it would cut out. My AFM was heavily worn but I managed to get it working okay but the idle was occasionally erratic even before the ECU let go. I had thought of repairing the ECU, but getting the ICs is tricky now and would require a partial redesign. Not really practical. There are a number of ways you can go with such a conversion; one would be to put the Haltech in the boot and use the existing loom. You could also keep the ignition system, as its perfectly up to the job and even the fuel injection. I did speak to Haltech about the latter and they recommended going with modern injectors to get the best out of the system. My injectors were so worn they needed replacing so I bit the bullet and had a new fuel rail made to fit stock bosch 4-hole injectors. I’d suggest it would probably work fine with the stock injectors if yours were good. The Haltech ECU and components are of excellent quality and their support is also excellent. They even dialed into my ECU before I kicked it over to check it for me and then did an initial adjustment to make it drivable. I wasn’t chasing power; I just wanted a reliable classic which I now have. Hot idle rock solid on 770RPM and smooth power delivery. There are a few tricky parts to this conversion, so I’ll share the gotchas I found. I do have drawings for all the brackets and air pipe I made. I’ll package up what I have and send it along. Would be great for us all to share our knowledge and help keep as many of these great cars on the road long into the future. I’m sure our shared expertise will help others create the system that works for them. For those gong the Haltech route I can even share my map which will help with the setup.
Your reasoning is impeccable, Randy. Providing there is motivation, time, competence and money available - even purists must at times compromise for lack of correct replacements…
I had already compiled a good deal of my notes on this project, it really just needs some time to finish off. Years of technical writing has left me a little particular in that regard. I’ll endeavour to send this along as chapters and will update as time goes along. It is pretty comprehensive but by no means a guide for the inexperienced. As for fuel consumption, it has made a difference, but I have not quantified this. Not really a difference in traffic but much better on a run. There are so many factors at play here and I am running sequential injection now with modern injectors let alone the benefits of the Haltech. One has to remember a large capacity old-school six coupled with a rudimentary 3-speed auto is never going to be the last byword in economy and efficiency.
Just my opinion, but if you are proceeding in chapters, (I, and I suspect most on here) would prefer the electronic stuff and theory first, which is your forte anyway, and may be almost written up
Harness details & fitting details next, (bet you have harness details already saved)
bracket dimensions etc last, most guys on her are good at bracket fab
Electronic theory not so much, I am ok on that, but there is a few guys on here forgot more than I know,they may chip in if they see and take an interest
Your system may be adaptable and applicable to other Jags
Dont know how long you have active been on this forum, I know I can look that up, but I had not noticed your posts before
Apologies on my part for any presumption on how you want to publish your IP
This forum allows for edits
I do understand any wish to make sure anything published on a public forum is to the standard one would want, which can be a very high standard
There is only so much that can be done; the engine, drive train and car is what it is. It’s 7 gears and modern engine construction that gives modern cars the edge - together with your modern electronics. Good work…
Can’t make a silk purse out of a sow’s ear is not the proper term for ‘our’ Jaguars - but to be kept in mind…
Good points, Tony. When I started putting my notes down in a Word Doc it naturally gravitated to a bit of theory of operation and why I chose the components I did. I’m sure there’s plenty better at the metal fabrication than I, so hopefully that bit will be easy. The part I found the hardest was selecting the parts. I couldn’t find anyone who had done what I wanted to do so was breaking new ground in a lot of cases. Something of a leap of faith in other words. I’ll endeavour to get part 2 out this week, as its nearly complete.
As I’m one day hoping to inject my Mk2 using in part XJ components, what you’re planning to write is of great interest to me and I’ll be following closely.
That’s the real attraction. It would be good to design a system, even if it never gets built. Either way, there’s a lot of bodywork to cut and weld first …
…anything is better than nothing
