G'day Guys.

I am still rolling with the 6CU ECU in my ole girl and was thinking of trying to upgrade to the 16CU.

If I can't get my hands on one yet I am going to do what other forum members have recommended at the bare minimum and take out the 6CU and give those solder joints a work over in my little workshop.

For those that hadn't been following it, I have been having some issues when in low idle and getting warm (i.e like at traffic lights) and I have been eliminating a few things here and there on this thread:

https://www.jaguarforums.com/forum/x...eriods-168508/

My question for this particular thread is more in relation to upgrading the ECU.

1) Is it simply just plug and play? (ie. straight compatible)
2) What are the main differences between the two?
3) What adjustments are there to be made when installing the 16CU?
4) What are some things to look out for in buying a 2nd had one? (I am assuming you can't get these new no more).

Cheers again

 

1) Yes
2) I dunno. "Improved circuitry"? Someone here will know, or you can probably find the answer on Bywater's AJ6 Engineering website
3) None that I know of.
4) Hopefully the seller knows if it was working properly or not and report honestly. Any obvious physical damage or water damage would be a red flag, obviously

Cheers
DD

 

1) as Doug said, Yes
2) Much more reliable componentry and circuits
3) none at all
4) check it actually works in your car.


In the UK there are loads for sale (like your car they are Lucas, non-cat, 12:1 compression) and even guaranteed rebuilds. The 16CU upgrade is one of the most important upgrades you can make to your car.
Greg

 

Thanks guys. Here I am just thinking it might be a good idea not realising it is something I should of have done a long time ago

So then.....anybody know what a good price is and what a rip off would be here in Oz money?

 

When was the 16CU introduced? I assume somewhere mid 80ies?

 

Sometime in 1984 build date, my car is an early 1985 and had it OEM, while 1983 cars are all 6CUs AFAIK. We can rely on PTJS to supply the VIN start number!
Greg

 

My 89 must have it then

 

My 5/85 Build had a 6CU, and it was an unmolested Aussie delivered car.

The Goose also had a 6CU, and is an '84 from memory.

 

Knowing Jaguar at the time, they probably just randomly used up stocks around 1894/85! Unless they palmed off the old stuff on the Aussies...
Greg

 

DAC 4119, DAC 4478, DAC 4586 and DAC 6336

These are the 12.5:1 ECU numbers without Cats.

They are in the UK, but skinny in the USA, due to different comp ratio engines.

 

Yep, being as how we Aussies are SOOOOOOOO special, that would be the best explanation of all.

 

Good question Daim, I too was wondering that.

Cheers Grant. My old girl is stamped with an AUG 85 build date. So I could get any one of these and I would be ok? What are the differences between these numbers anybody know?

I see on ebay they have some on offer but they mostly the appear to be for Marelli Engines. One picture has "32CU" on it so definitely not what I am after.

Cheers again.

 

Paulying
The 36CU used on later V12s will NOT work in our cars.
Of the numbers Grant listed, I believe the last one, DAC6336 might be for Marelli ignition cars without cats (if they exist, which I think they do). I am pretty sure the ones starting with 4 are all OK.
If something suitable turns up in the UK I'll drop you a PM, as I suppose if you are marooned on the rig the postage time will not matter too much?
Finally, Roger Bywater at AJ6 knows all there is to know about these things, and if needed, he can modify any 16CU (Marelli, cat, non-cat etc etc) to work properly with the Lucas ignition. If offered one and you are not sure, I expect he would tell you if it would work or not.
I think in the UK you will have to pay around 100+ UKP for one, say 200/250 AUD.
Greg

 

I have one! I have a Marelli non cat from factory I could - if I find the ECU - see if DAC6336 is the number...

 

Thank you again guys.

Greg I would very much appreciate that PM if one pops up.

Grant has mentioned also that the DAC4586 is the Austraian spec Non Cat ECU, of 16CU type (Cheers again).

James (34by151) knows a fellow near his house that has them sometimes and I will try that avenue first to see how I go. That way I may be able to plug in and "try" before I buy incase she's a dud. From my other post:

 

My question would be will a 16CU from a Marelli car work? The engine speed signal was changed from the Lucas ignition cars, I would imagine the signal conditioning circuit in the Marelli iteration of the 16CU will be different.

I have just modified my Megasquirt engine speed signal conditioning circuit to work with the Jaguar VR sensor as before it would not read the signal, ie no engine RPM.

 

My understanding, based upon the fact that a friend is having a Marelli 16CU modified so it will work with a Lucas ignition car, is that it will not. However, the mod required is not particularly expensive or complex, though I have no idea at all what it consists of.
Roger Bywater at AJ6 would be the person who can give us a definitive answer.
Greg

 

The tach signal from a coil/ignition amp is very dirty and looks like a spike and requires a lot of signal conditioning so the ECU can trigger on the signal.

I haven't scoped the Marelli signal but I would expect the output to be a cleaner squarewave. This will allow the Lucas ECU to trigger. So the signal conditioning circuit is not required. I will have a look at my ECU to see what components were removed. I would not expect Jaguar to have made any changes to the PCB.

 

Digital P: type 6Cu cat type:
DAC 2597
DAC 3586
Non cat type:
DAC 2596
DAC 3062

Type 16CU catalyst 11.5:1
DAC 4118,
DAC 4585,
DAC 6335,
DAC 6337
Not catalyst 12.5:1
DAC 4119,
DAC 4478,
DAC 4586
DAC 6336
Not catalyst 11.5:1
DAC 6338.

All will work with Marelli and with Lucas.

 

Are you 100% sure that this is true? I highly doubt the no-cat ECUs will work properly with a catalyst Lucas or Marelli. But I could well be wrong, so I am just enquiring from where you found the info.
Greg