Thread: range-rov fuel save mod

there certainly is room for improvement in the fuel system of land rover v8's, but if it's that simple, wouldn't the factory have done it themselves?

It was probably set that way to meet emission standards; a rich mixture may have proved necessary to keep Nitrogen Oxide emissions low enough.

It may also have been necessary to run the mixture rich to ensure that in all circumstances excessive combustion temperatures did not cause engine damage.

John

Sturdy shoes and a big hole in the floor should save fuel!!

Are they just changing it from open loop to closed loop?

The non-cat discos like mine don't have O2 sensors and run an open loop system. Without O2 sensors the 14CUX ECU looses the ability to be adaptive. With O2 sensors the ECU is able to determine whether the air/fuel ratio is lean, rich, or okay.
I think D1's from 98 have cats and run the closed loop system. The 14CUX has a tune resistor that can be changed to suit different world markets. I've read that later ECUs don't have the tune resistor and just run a different fuel map chip.

Given that it didn't come with cats from the factory I'm guessing they ran an open loop because our emission standards were a bit behind other countries and they could get away with not fitting cats or O2 sensors to save money.

Would they just be adding O2 sensors and changing the tune resistor or fuel map chip?

I have always wondered whether the circuitry is in our 14CUX to be able to run O2 sensors. The USA version has a diagnostic display as well as closed loop.
The 14CUX here does run much richer than 14.7 :1 . If O2 sensors could be fitted and the ECU go closed loop until say 50% throttle, then I am confident this would give a big improvement.
Anyone in Mebourne want to investigate?
Regards Philip A

I asked them about this and essentially they simply put in the US tune and include an O2 sensor. For normal throttle positions the ECU takes it's input from the O2 sensor, when you go full throttle, the AF meter overrides it.

If you're sticking with petrol and plan on doing plenty of km yet, it isn't a bad option.

Originally Posted by PeterM

I asked them about this and essentially they simply put in the US tune and include an O2 sensor. For normal throttle positions the ECU takes it's input from the O2 sensor, when you go full throttle, the AF meter overrides it.

If you're sticking with petrol and plan on doing plenty of km yet, it isn't a bad option.

do you know how much they charge?

thanks rob.

All the wiring and support is there at the ECU ,( I even get a Lambda A and B output page on Rovacom for O2 sensor diagnostics...), there is just no wires at the ecu plug for the O2 sensors. These can easily be added, in the front engine pipes close to the join of the two primary pipes on each side.
I would then suspect that they actually change the tune select resistor value for the US spec, and it should work then. Interesting, I might give it a go.

JC