Discovery TD5 - 16MPG !

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Desert Cat

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A 2001 Discovery TD5 ~ 300K KM

For a long time mine runs as 16 MPG :(

New geniune Land Rover MAF
New genuine Land Rover fuel filter

Could it be related to a failure at the FPR?
FPR in not leaking a drop, but I could not think of a different cause.

njectors seals were never replaced, no fuel @ engine oil...:)

I own the new gen NANOCOM at hand for reading information, but it's limited...
Any ideas?
 
what do you mean the nanocom is limited:confused: ...can't you check if there are fault codes and read some live data with it?

read live data at idle and at 3000 rpm and post here your findigs about, air flow, ambient pressure, manifold pressure, inlet air temp, fuel temp, coolant temp...or upload a sheet with the data then we'll see...the fact that the MAF is new doesnt mean it works...do you still have EGR?
 
have you cleaned off the map sensor? i had poor milage until i took off the maps sensor and then took off the inlet manilfod to clean, my inlet was nearly 2 inch thick in crud, the ports were so blocked i couldnt get a finger in,, after the clean im getting around 25mpg (7mile journey 2 work dual carrige way and town) plus its auto
 
Does it still have an Egr? Removing that should help, exhaust manifold clean/replacement? Brake caliper sticking?
 
what do you mean the nanocom is limited:confused: ...can't you check if there are fault codes and read some live data with it?

read live data at idle and at 3000 rpm and post here your findigs about, air flow, ambient pressure, manifold pressure, inlet air temp, fuel temp, coolant temp...or upload a sheet with the data then we'll see...the fact that the MAF is new doesnt mean it works...do you still have EGR?

+1

Fery helped diagnose an issue with poor mileage on mine, turned out to be a combination of degraded coolant temp sensor and a failed thermostat - ie engine was running too cool AND reporting it was running cooler, so ECU was chucking more fuel in.

Is it smoky?

Is your FPR leaking? :D

When was the intercooler last flushed - makes more of a difference than you'd think.
 
Last edited:
A 2001 Discovery TD5 ~ 300K KM

For a long time mine runs as 16 MPG :(

New geniune Land Rover MAF
New genuine Land Rover fuel filter

Could it be related to a failure at the FPR?
FPR in not leaking a drop, but I could not think of a different cause.

njectors seals were never replaced, no fuel @ engine oil...:)

I own the new gen NANOCOM at hand for reading information, but it's limited...
Any ideas?


Is that round town driving or on a run?
Mine is probably similar round town stuck in jams,but probably doubles on a run to 30 something.It is a very busy engine just sitting stationary hour after hour.Also I run bio which has less energy than dino diesel ,so maybe I have to accept lower figures anyway.
 
My 300TDi did about the same on my first tank full that I measured. For me it turned out the odometer was reading wrong but the speed was correct. I am actually doing 1.5 x the displayed distance. That made my 17mpg more like 26mpg and more believable.

Probably not your problem but a quick run with the satnav set to trip computer may rule out the problem.
 
Well here's some information reading the NANOCOM:
Engine speed - 3022RPM
Coolant temp - 90.3C
Turbo pressure - 0.81
Ambient pressure - 98.98
Air flow - 437.2
Air inlet - 47.0C
Fuel temp - 75.1C

Idling:
Engine speed - 757RPM
Coolant temp - 90.3C
Turbo pressure - 0.01
Ambient pressure - 100.75
Air flow - 57.4
Air inlet - 47.4C
Fuel temp - 74.8C

Does this tell you something regarding the fuel consumption?
 
replace the air filter and the depression controll valve... the readings are looking good but the fact that the AAP drops with almost 2kPa when you rev it means it's some restriction in the air inlet

it would be good for you to answer to all the questions...i mean about EGR too.
 
Actually I had replaced the depression control valve 2 month ago with a genuine land rover one
Could the high fuel consumption is due of a bad fuel pressure regulator? It's not leaking at the moment.
Air filter was replaced as well, was thinking about Cleanning the inter cooler but not sure it can have a big influence
 
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