TD5 poor fuel consumption

hi all,
any idea why I should be getting such lousy fuel consumption?
2001 Disco 2 TD5.. with either K&N air filter or std paper type, silicon hoses, upgraded intercooler, EGR blanked, Nulon oils, new fuel filter and non-leaking fuel pressure regulator, 2x MAF's tried (1 old & 2x new) TD5-Alive boost box, remapped ecu (either standard or power remap loaded via nanacom) and constantly getting around 16-17L/100km (approx 17.5-16.5 mpg) !!!
I get this mileage whilst towing my 21ft caravan around Australia (to be expected.... and yes.. we do have bitumen roads in Oz) ... I also get the same mileage when not towing at all :screaming_bug_eye_f
Sensors in the airbox and inlet manifold have been cleaned several times but not tested or replaced... not sure that they would have this big an influence as well I have an injector to account for such bad consumption (when not towing).
Could I have an injector issue? I run a performance additive (either CEM CleanPower or DieselPower fuel additive most of the time)
Got me a little stumped

Heavy right foot.

Could be worth replacing the coolant temp sensor, they report low with age making the ECU chuck more fuel in...

Make sure you replace with a genuine Bosch sender, not the cheapo ones on fleabay.

PS, know anyone with nanocom? Record data and post here.

bankz5152 said:

Heavy right foot.

Click to expand...

actually... no!!
I drive very conservatively

Bennehboy said:

Could be worth replacing the coolant temp sensor, they report low with age making the ECU chuck more fuel in...

Make sure you replace with a genuine Bosch sender, not the cheapo ones on fleabay.

PS, know anyone with nanocom? Record data and post here.

Click to expand...

interesting suggestion re: temp sender.
do you think it would make that big a difference? ... ie. pretty much same fuel consumption when towing (2500kg caravan) or not.
Hard to see why I consume around 16L/100km when towing (which I think would be a reasonable figure) and when disconnected and driving (with a light foot) on mostly level ground and bitumen roads I'm still using the same amount

I do have a nanocom... what info would you like to see?

Go into the instrument view and record data for while when at running temp and driving about then post here - you'll need an SD card in the nanocom (assuming it's EVO) in order to save the data file.

When I had a dodgy thermostat and a tired sender my fuel consumption was so poor I only got 350 miles to a full tank (that said I normally only get 480 due to muds & mods)...

+1^^^ ...some live data would be relevant...that constant big consumption which is regardless of the load might be the result of the management going on a default mode caused by one of it's elements

that temp sensor theory is verified, i saw it not once cos the temp sensor is a simple resistive NTC unit which looses it's qualities in time and as the gauge goes to the middle between 70-80*C you'll not notice it...the Td5's optimal consumption is at around 92*C so if the input is constantly around 80 more fuel than needed will be injected...also AAP(airbox sensor) input will affect the consumption and other common thing is the IAT side of the MAP/IAT sensor which used to fail

didnt you notice any black smoke under hard acceleration?