Disco 1 tuning resistor

[AncientGeek]

Disco 1 3.9 petrol 1997. Anyone familiar with the tune resistors?

To cut a long story short I measured across pins 5 and 27 of the ECU connector and got near as as dammit 3900 ohms. I then (eventually) found the resistor (taped inside the loom) and indeed it is a white one as per Land rovers docs that says white 3900hms is UK/European with cats

So somebody has switched to the UK/EU cat map with the resistor (I'm leaving out all the other horrors that I found, scope for many more threads on that).

So what colour were the SA spec Disco 1 tune resistors? I would guess red as that is for Australia and the rest of the world but maybe they used the other green and yellow non cat resistors. Our local Landy guys are not sure.

[stretch]

Ever found out about this? I just located a red one on mine

What would be the best suited for .za?

[AncientGeek]

Never took it further but I know the Aussies like to switch to the green one (470 Ohm) You can make up one yourself and try it. The white one is ONLY for use with the correct lambdas.

Some fascinating stuff here http://code.google.com/p/rovergauge/

[LRwit]

I also had a red one in my '95 manual with no cats.

[LRwit]

There is a bit about tune resistors here: http://www.v8engines.com/carbs-2.htm#Tune-resistor

[LRwit]

Even better:
http://www.britishv8.org/articles/rover-14cux-efi.htm

I suspect the green tune resistor would be for countries with true high octane petrol whereas the red one is for sad countries like ours where fuel quality is dubious.

[LRwit]

I suspect the green tune resistor would be for countries with true high octane petrol whereas the red one is for sad countries like ours where fuel quality is dubious.

I should add that high octane fuel is ONLY useful on high compression engines where it helps to avoid detonation/pinging/knocking. There is no benefit to be had by using high octane fuel on low compression engines.

[stretch]

What octane was used in the UK 15 years ago then they mapped the ecu?

[NewLandy]

My 3.5 V8 had the yellow resistor, Saudi..

[stretch]

K, I measured pin5 to ground, its on 470R - so its mapped for UK no cats,

can't find any details on what the difference is between UK and Aus maps

[AncientGeek]

So you painted it blue so it changed to 470Ohm?

I would hazard a guess that the UK map to be a bit leaner at WOT because of the better petrol quality.

With the roverguage software you can examine the maps and look at the difference. I bet you would find they are almost identical.

[stretch]

I made the interface for rovergauge yesterday - pretty cool i must say, saw that everything seems to be working

[stretch]

it's uhmm, exactly the same...

[stretch]

https://www.dropbox.com/s/tt7ctfem57...rovergauge.jpg

[LRwit]

it's uhmm, exactly the same...

This makes me think that by applying different values of "tune resistor" has an analogue effect on the overall enrichment being applied by the ECU? - similar to tuning the screw on the MAF?

Hmmm... Something to investigate one day...

[AncientGeek]

Ho.
I was almost right.
If you can access the cat (white) map it should be different.
If an analogue effect why bother with multiple maps? Maybe was intended for future use. The programmer did not adhere to the YAGNI principle. (You aint gonna need it)

[faniedup]

I fitted a variable resistor, trying all the maps, could not really feel any difference by the seat of my pants, except the one for cats, (mine is fitted with cats but resistor changed to red and lambdas unplugged)

If I plug the lambdas back in and use the Cat map, it gets sick, maybe the lambdas are shot.

[Hagu13]

Stretch, which 2 maps did you compare?

AUS/ROW vs UK?

I have a red AUS?ROW resistor if anyone wants it. THe loom is scrap now

[stretch]

Stretch, which 2 maps did you compare?

AUS/ROW vs UK?

I have a red AUS?ROW resistor if anyone wants it. THe loom is scrap now

Yes, Aus and UK - exactly the same. /me starts saving for a spittronics

[AjayDisco]

Yes, Aus and UK - exactly the same. /me starts saving for a spittronics

What does it cost for the spitronics setup ? Rob ?