Okay... after a little searching:

Jaguar differs bewteen VIN and cat/non cat.

In my case an 89 Marelli with not cats, DAC6338 would be the right one.
A Lucas without cats would be DAC6336/DAC6336E.

A Marelli with cats would be DAC6337.
A Lucas with cats would be DAC6335/DAC6335E.

If they were interchangable, then I doubt Jaguar would have all these different one. Especially since the catfree models run without the interference of lambdaintegrators (lacking the lambda sonds).

So I don't think you can simply interchange as you want. Especially as some have higher compression than others... And as the sensors are rather rudimental (no MAF, no knock sensors, only a few 'blunt' sensors, like an air temperature one and some coolant sensors) I assume the ECU runs only on the mapping and has very limited adaptabilities...

Btw. The numbers posted above are from Jaguarclassicparts and only for prefacelift models after the HE introduction.

 

Well thanks to Greg in France we have a winner!! The sticker says DAC4586 so she's a goer right?

$175 Pounds including postage.

Also does anybody know what the 84527D denotes?

 

Nope.

Probably Greg, or Alan, did that to keep you occupied until you get home.

I have seen those numbers, never bothered with then, as the DAC is the key.

Well done on the ECU.

 

Ha ha ha....there is many things under that bonnet to keep my mind occupied!

This was who I ended up going with:

Just Jaguar XJS Parts and Spares, all models 1975 to 1996

Thanks again Greg!

 

From AJ6 engen LUCAS EFI / AJ6 Engineering

6CU Part Numbers and Applications.
All are preceded by DAC.

1926 - pre-HE Cat
1936 - pre-HE non-Cat
2596, 3062 - HE non-Cat

16CU Part Numbers and Applications.

All are preceded by DAC.

4118, 4585, 6335 - Lucas ignition, Cat
4119, 4478, 4586, 6336 - Lucas ignition, non-Cat
6337 - Marelli ignition, Cat
6338 - Marelli ignition, non-Cat
2597, 3586 - HE Cat


My previous message with the CR

 

Thanks mate. I appreciate the info.

I purchased the 4586 as mine is Lucas ignition non CAT. I do wonder what is the difference between numbers in that category though.

Anyway, got mine coming in the post. Worked out about $290 AUD incl. postage so I think that was a good deal.

 

Hi !
I was taught the "art" of soldering in the USAF using the NASA "Zero Defect" procedures.
The most important concept I got from the training was that the solder was not
meant to be the main medium for electrical connectivity for a circuit.
It was meant to be a mechanical means to secure points of contact together and to provide a gas tight point of connection.

I have removed the solder from printed circuit modules where the solder had
deteriorated or developed cracks and had the modules function again by applying
new solder and cleaning the surfaces.
Just heating and reflowing the old solder is not recommended for long lasting results.

The best results were when I removed ALL of the old solder and then cleaned the
contact surfaces with a contact cleaning product. I then made all the connection points
make contact firmly with each other and then applied the solder to make a firm bond.

I have found some circuits that carry huge loads of current (amps) where the wires were
just inserted in a puddle of solder and not in actual physical contact with each other.
These contact points generally have large areas of printed circuit board starting to turn
brown or black due to the resistance of the solder generating heat.

The U.S.A. EPA has had a huge effect on the makeup of solder in the U.S.A. in trying to
eliminate lead (PB) from our environment.
Most of my electronics soldering is now done with a mostly Silver (AG)/Tin product.
It requires a higher melting point and some oddball forms of flux components but
it seems to be a reliable product for most electronic uses.
In high Sulphur gas product areas the Silver surface will turn black if the Silver is not
sprayed with protective coating.
I coat the modules with a polyurethane spray product for devices that are exposed to
high moisture content occasionally like automobile interiors. Especially convertibles.
The coating provides a shield against the crud in the air that seems to exist only under
the dashboards of automobiles that causes circuits to crumble over time.

When done correctly the solder joints will look nice and "shiny" and will provide
reliable service for a long time.

Regards and POR - Press On Regardless

 

Thanks for sharing scarbro2011. Wise council indeed.

I would have to agree that removing old solder, and cleaning up the area before re-appling new is definitely the better option than re flowing old solder.

I used to have a awesome Hakko solder sucker when I worked in an electronics workshop repairing traffic signal circuit boards but that was bloody expensive. Now days I use one of those hand held solder suckers with a spring you push down.



I find them pretty good for small jobs.

Never had much luck with the de-soldering wick.....


guess I was spoilt with the Hakko Solder sucker many years ago.


My weapon of choice for soldering though is the trusty Wella WES51:

 

Well I got home after a month being offshore and the next day my ECU arrived. Pretty good customer service from JustXJS over there in Eng-a-Land http://justxjs.co.uk/



Perfect timing! Only trick is not much point plugging it in just yet as I have to finish my other project (Fuel Injector Harness).

Stay "tuned" for a progress report a little further on down the track.

 

The 6CU in my 1983 XJS died a few weeks after I bought the car.
I bought a cheap 16CU that came out of a used 1986 XJS.
I put the 16CU in my 1983 XJS and I have had no problems with it since.
That was about 12 years ago.

 

G'day Guys.

I finally got around to upgrading my 6CU to the 16CU.

Pretty much just plugged her in and let er' rip. She is going like a dream (as far as I know).

Is there anything else I need to do to fine tune it after installation?

 

DRINK MORE, before going back to the rig.

Seriously, nope.

Maybe a tickle of the idle fuel "pot" as I mentioned a very long time ago. If you have forgotten here it is again.

Adjusting the ECU fuel pot.pdf

 

Well...if the WoOz says to drink more then I am just going to have to oblige


Thanks for the PDF too!

 

Greetings

cool thread

i have been lookng at upgrading the 6CU in my 84V12 ....aka the Mistress.

been looking at a new one, a 16CU and a AJ6 engineering Superenhanced Job .... my concern with the used 16CU is they are getting old and not really sure of the condition of the unit when i get it.
The AJ6 units seem reasonabley priced compared to the costs of a new unit ... ie megasquirt or something like that.

Advice and comments are welcome, especially with the AJ6 products

all good

Darren

 

I've had AJ6 do the "Superenhanced" thing on two 16CU units. They've worked just as advertised

Cheers
DD

 

I am with Doug on this one.

The s/h now are OLD, and the issues with the donor car are unknown.

I would go AJ6 if I needed that today.

 

AJ6 enhanced ECU and large throttles will transform the car, it is an absolutely great mod. I have had it on my car for about 20 years and helped three other people do theirs. Absolute magic and straightforward to fit.
You have to supply a 16 CU to AJ6 for them to modify, so you need to buy one and send it to them, together with the throttle bodies and air boxes from your car. So it is worth buying a 16 CU and as it is a straight swap for the 6CU using it until you get it modified by AJ6.

 

I might have an 16cu ECU you can use,pm me and ill dig it out

 

Greg, the ecu, large throttle kit sounds great, but that's going to be about $2000 Canadian.

I think I'll start with a 3.54 diff and see how that goes. Then maybe a T700 gearbox. I can do the T700 gearbox for about the same money as the large throttle kit, and I would expect that the gearbox mod would yield more performance.improvement.

I love these cars but it's getting costly. I could buy an XJR for the same money. I still like modifying the XJS though.

Cheers,

Rob

 

Going from the 2.88 to a 3.31 diff has been one of the most satisfying and effective changes I've made.

I had an XJR as a daily driver for years. Great car in many respects. And fast! But not particularly easy to own at times. I used to call it "The Tormentor".

I've always been interested in power/performance but budget and practicality plays more of a role as the years go by. If I want more power than a few simple mods can deliver I'd be really tempted to simply go out and buy a car that has the level of power/performance I want. But that's just me

Cheers
DD