www.jec.org.uk

Well, after 2 years of hunting. Long and hard, I have pulled together a diagnostic and full mapping system for my XJR-S. This is beyond the dealer fault diagnostics, but able to modify all elements of the map. Even convert to EDIS if I wanted to apparently. I could've easily bought another XJS for what it cost though. I've convinced my wife it's a family heirloom.

This system will work on the pre cat and post cat systems.





The software is 100% useless without this box. It's foamed and glued together so trying to replicate it will destroy it.





This is from Bloxham so has probably been plugged into some very special cars through its life.

Great piece of kit! Well done! How about writing a short piece for the magazine and send it to Brian Harris when you've used it on your car? You could also offer a diagnostic and mapping service for other XJR-S owners and maybe recoup some of the cost!

Paul

Great piece of kit! Well done! How about writing a short piece for the magazine and send it to Brian Harris when you've used it on your car? You could also offer a diagnostic and mapping service for other XJR-S owners and maybe recoup some of the cost!

Paul

Thanks Paul, two very good ideas. Particularly the latter. It's basically stopped dead a restoration on another car, because I had to find funds to buy it, this wasn't something I was willing to miss out on! I've literally got another car sat mostly in primer now.

I've lost count of the number of desperate threads concerning Zytek. I think publishing an article for the XJS pages in the club magazine and offering a (chargeable) service for owners would be a real value-add.

Cheers, Rich

Well, it's working!

Thrown up my first issue with my car too... Lets see if someone can diagnose that from the second photo





Hmm...!

I'll spend a little more time on it before I run out any buy a replacement... SPD1130...

XJR-S,


.. and maybe charge the car's battery?

Paul

XJR-S,


.. and maybe charge the car's battery?

Paul

Haha. My Bosch silver battery could start a tank and never reads more than 12.1. So with all the ignition and interior lights on I was happy with 11.9!

XJR-S, Do you have the Jaguar Sport S80 publication? I have it on PDF if you need a copy.

It's not exhaustive, but does detail the Zytek system somewhat. If you send me your email address via PM I will gladly send it as an attachment.

XJR-S, Do you have the Jaguar Sport S80 publication? I have it on PDF if you need a copy.

It's not exhaustive, but does detail the Zytek system somewhat. If you send me your email address via PM I will gladly send it as an attachment.

Very kind of you, I've checked and yes I've got that one, it's the US JaguarSport book. I've got it in hard and soft copy fortunately.

Car developed a loud buzzing noise in the driver's butress on the way home today.... Eugh.... Now I will probably need that manual tonight! Curse of the daily driver.

XJR-S, Do you have the Jaguar Sport S80 publication? I have it on PDF if you need a copy.

It's not exhaustive, but does detail the Zytek system somewhat. If you send me your email address via PM I will gladly send it as an attachment.

Very kind of you, I've checked and yes I've got that one, it's the US JaguarSport book. I've got it in hard and soft copy fortunately.

Car developed a loud buzzing noise in the driver's butress on the way home today.... Eugh.... Now I will probably need that manual tonight! Curse of the daily driver.

That loud buzzing was from the fuel tank, the rochester valve had packed up...

Never a dull moment!

Sorry to revive an old topic, but more of the XJ220's are coming into the USA every month now that the 25 year rule allows us to import them with only "safety" inspections every year (except in California where they still must meet emissions testing). I am in the midst of recomissioning a 220 I recently purchased, as it was never driven (has 400 miles on it). The teardown, cambelts, bag tanks, seals, etc. are all pretty straightforward, but no one here has the Zytek diagnostic kit for the XJ220. I heard there was one in North America but no one knows where it is. So:
1. Is there another way to communicate with the Zytek unit? We do have an old Toshiba laptop running Windows 3.1 or similar, with a serial cable that my technician tells me he has used before on his own Xj220 which he federalized 10 years ago. But from what I've read, that little blue box is necessary to interface with the ecu? Unless he hacked it somehow.
2. Is it necessary to reprogram the ecu after a rebuild?
3. Any more of these diagnostic kits available on your side of the pond? Where would be a good place to look?
I really don't want to replace this system with a modern Motec or similar and spend another $30-40,000 on top of the rebuild costs. And I like the originality of the Zytek, and I've heard it's robust. Any advice on this Zytek system much appreciated. I did contact Zytek (now Continental) but they don't have any old units lying around, and can't make me a new one. Thank you.
Steven

Hi Steven,

You'll have seen my reply to you on jaguarforums.com. As I mentioned, GC Performance in Tennessee must have had a Zytek tuning unit as they were the XJ220 Specialists in the US. I'm not sure if they've completely given up on 220s, but if so, they may be interested in selling their kit?

As you've appreciated, Zytek is really rare, although paradoxically, it was a popular setup for a number of cars and race series in the 90s. And that might be a way to consider sourcing a kit.

Jaguar also used a Zytek setup on the 6.0 XJR-Ss. I appreciate that there were only 100 taken over to the US, but there may be some Jaguar or independent dealers over there who still have some kit. Although the settings will be very different, I suspect there's lots of similarity in the cables, (Toshiba?) laptops and ecu modules that Jaguar used.

Zytek was also used in a number of British Touring Cars in the 90s. That's a race series known as the BTCC (still running today). A number of the 90s teams used Zytek controlled ignition and fuelling. So maybe an investigation into the old teams could prove fruitful.

Zytek was also used in a number of other race series, some Le Mans Race Cars (Nissan etc) in period and other race cars.

As regards the UK Jaguar scene, Don is the obvious candidate (although he obviously won't be selling his setup!). But some of the respected Jaguar independents such as David Marks Garage have dealt with XJSs for many years and will have Zytek stuff for their XJR-S maintenance regime. Again, whilst I don't think any of them will be in a rush to sell you their original kit, they may be able to advise you on ways in which cables and interface units could perhaps be built to emulate the original.

I also used to have a contact in New Zealand who owned an XJR-S and had technical documentation etc on the XJR-S Zytec setup. I'm not sure if there would be value in a copy of that documentation and how it may or may not relate to XJ220 use. But I can try and put you in contact if you wish.

The shortage of all Zytec units, knowledge etc is a particular concern to 220 owners. When our 220 was recommissioned, it needed a new Zytec ecu, and fortunately Don was able to supply one. But there are almost none left now. Which means that the development of a modern ecu ignition and fuelling unit is urgently required. I suspect Don and Justin have been working on a potential solution in the background.

I hope that's of some use. Do get back to me if I can help in some way.

Good luck

Paul

Afraid I've now sold both of my diagnostic equipment sets, I do still however still have the software and one cable for the xj220 avaif necessary.

I'll take the cable for the xj220. Is the software for the 220 as well?
I know the cable alone won't work, but I'll find an interface somewhere....I hope.

Kindly PM me at ssjsolomon@aol.com with price and shipping to NY. Thank you.

It should be possible to open the cable unit up and recreate a clone, even if the components are obscured with mastic. You know that information comes out of the Zytek in a not too dissimilar way to OBDB1 form and you know how a serial port on a PC works. Further to that, this is 1980s technology and not being a chip manufacturer themselves, the most they can have done is put a custom EPROM into the dongle, all of which can be remade. If you know the pinout of the loom to the Zytek ECU, you're halfway there.

Going down this route, everyone who wants a cable should be able to have one. The XJS software works fine in a DOS box under Windows 2000, so a super old laptop isn't necessary.

kind regards
Marek