John a Posted December 2, 2013 Share Posted December 2, 2013 Hi all I've got a problem with my v8 discovery, it runs 40litres per 100 kms so on a full tank I get 200kms. I've changed the plugs,leads,dizzy cap an button. Fuel pressure is 28 psi , air flow sensor is working, stepper motor working, changed all vacume lines..????? Any advice would be a great help. Regards John Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 2, 2013 Share Posted December 2, 2013 Coolant temperature sender is a first stop, that and check your thermostat is working. Quote Link to comment Share on other sites More sharing options...
luke keeper of badger Posted December 2, 2013 Share Posted December 2, 2013 second that bowie69 also Tyer pressure/tracking,or dragging brakes i can do about 220 mile to the tank in my disco on road tyres...it goes down a bit with muds luke Quote Link to comment Share on other sites More sharing options...
John a Posted December 2, 2013 Author Share Posted December 2, 2013 I will check the coolant temperature sensor and thermostat on the weekend and I'm using road tyres at the moment will the sensor make that much difference on the fuel consumption as that's a lot of fuel (40L per 100kms?) Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 3, 2013 Share Posted December 3, 2013 If the temperature sensor is broken, it will be like driving with the choke always on as the ECU will be in cold-start mode (like cold start on a frosty day in the arctic!) Quote Link to comment Share on other sites More sharing options...
smallfry Posted December 5, 2013 Share Posted December 5, 2013 I will check the coolant temperature sensor and thermostat on the weekend and I'm using road tyres at the moment will the sensor make that much difference on the fuel consumption as that's a lot of fuel (40L per 100kms?) Yes it will ! My Astra is diesel, but the temp sensor was faulty and it went from a regular 60 - 62 mpg down to 40...................... I believe most, if not all vehicles nowadays can have this problem, and in the winter I now cover half the radiator to get it to warm up quicker too, in order to retain the fuel milage, but This is more of a problem with diesels, which take longer to heat up in the first place. Quote Link to comment Share on other sites More sharing options...
Nigelw Posted December 5, 2013 Share Posted December 5, 2013 Think it may also depend on your driving style, I had my 3.9 running tip top and could and regularly did return 35L/100Kms but when you got a V8 auto you can indeed drive it like you stole it Are there any other symptoms apart from high consumption? How long have you had it? has it been like this the whole time? I had a lambda issue once which resulted in rougher running and worse consumption, just wonder if you have running issues also? Quote Link to comment Share on other sites More sharing options...
John a Posted December 6, 2013 Author Share Posted December 6, 2013 I've had it for 4 months Nigel and it's always been like this,I'm light footed so I don't think it's my driving style...if this is how much fuel it is going to consume I might as well do away with the injection and change the manifold and convert it to carby? Quote Link to comment Share on other sites More sharing options...
DJB1140 Posted December 6, 2013 Share Posted December 6, 2013 I would agree with above, coolant temperature sensor is the most likel cause. That consumption is exceptionally high. I can get 15 mpg (18 l/100 km ) towing a 1.6 tonne caravan out of my 2002 V8 auto Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 6, 2013 Share Posted December 6, 2013 if this is how much fuel it is going to consume I might as well do away with the injection and change the manifold and convert it to carby? Then you'd lose even more fuel (& performance)! If you're going to be drastic, megasquirt it! Can also be dodgy airflow meter, air temp sensor (in airflow meter), or lambda sensors. Quote Link to comment Share on other sites More sharing options...
Nigelw Posted December 6, 2013 Share Posted December 6, 2013 I've had it for 4 months Nigel and it's always been like this,I'm light footed so I don't think it's my driving style...if this is how much fuel it is going to consume I might as well do away with the injection and change the manifold and convert it to carby?Take it from me, the Rover EFI system is actually very reliable, and inexpensively simple to maintain, normally you should be half that consumption on a bad day! Don't waste time nor money on carbs without first sorting out this problem, carbs may seem like good idea but almost without a doubt unless they are new you are just buying other peoples problems and cast offs.Start cheap and work your way through the system, we are all here to help. Quote Link to comment Share on other sites More sharing options...
John a Posted December 6, 2013 Author Share Posted December 6, 2013 Take it from me, the Rover EFI system is actually very reliable, and inexpensively simple to maintain, normally you should be half that consumption on a bad day! Don't waste time nor money on carbs without first sorting out this problem, carbs may seem like good idea but almost without a doubt unless they are new you are just buying other peoples problems and cast offs. Start cheap and work your way through the system, we are all here to help. Morning all I tested the coolant sensor this morning and it was reading 320 ohms is that normal when the car is hot? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted December 9, 2013 Share Posted December 9, 2013 Looks about right to me, puts it at 79 DegC ish. Quote Link to comment Share on other sites More sharing options...
Rangy35 Posted December 10, 2013 Share Posted December 10, 2013 Have you done a compression test, hot and cold, wet and dry? Quote Link to comment Share on other sites More sharing options...
Nigelw Posted December 10, 2013 Share Posted December 10, 2013 Lamdas next, find them on ebay a lot, I did actually use a multi purpose one and doctored the wires to suit, as the €210/each was a bit rich for my blood from Land Rover Herentals. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted December 10, 2013 Share Posted December 10, 2013 Or bin the lambdas and change the 'tune resistor'... Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted December 10, 2013 Share Posted December 10, 2013 ^ I'm with bowie on that suggestion and I would also still change the cts as they can read ok and change as warm up Lastly disconnect afm when warm and advise if same better worse ? Quote Link to comment Share on other sites More sharing options...
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