This is slightly off topic but not entirely. A few months back, my brother purchased a '97 Discovery for the wife to drive, a Red ES with the 3.9 and auto and about 180,000kms on the clock. She adores the thing but they soon discovered that the fuel consumption was abysmal.
Not just 'V8 4wd' abysmal but seriously bad. It ran ok, but for the occasional misfire but never managed to achieve more than 280kms from a tank of fuel. I had a 3.5 disco years back that did 450-500kms per tank and the local Landy specialist reckoned that it should get a comfortable 400kms per tank even around town.
I am fairly unfamiliar with the efi so he took it to the Landy guys who took a quick look under the bonnet and discovered that- a: the serpentine belt had been creatively routed and the water pump was running backwards, and b: several of the minor vacuum hoses had also been randomly fitted including the cruise control and fuel pressure regulator.
They fixed these and sold him some injector cleaner to put in the tank, but said that as it had probably been running with excessive fuel pressure for god knows how long, chances are the valves would be all carboned up and would probably be the cause of the intermittent misfire. Unfortunately their tweaks didn't help so we bit the bullet and I pulled the heads off. There was not massive amounts of carbon buildup on the valves but the valve seats were pretty poor so we had the valves ground. The reconditioner said it had 4 slightly bent valves!
All was reassembled, cleaned and tidied and the engine runs beautifully. Smoother with a bit more power and sounds great. However, the fuel economy is still exactly the same. :x He has brought it back in to work to tidy it up and prepare it for sale but I would really like to be able to fix it for him. He did casually mention when he brought it in that it doesn't actually shift into 4th gear 'til 80kph! I checked and found the kickdown cable to be overtightened by about half an inch so I fixed that but I don't know if that would be enough by itself for a vehicle that rarely sees the motorway in regular use.
I spent a bit of time fiddling with it this avo and put a colourtune plug in it which showed a perfect flame, also, it doesn't blow any smoke so I am fairly certain that the engine is not the issue but I'm running out of ideas.
Any thoughts, good people?
Not just 'V8 4wd' abysmal but seriously bad. It ran ok, but for the occasional misfire but never managed to achieve more than 280kms from a tank of fuel. I had a 3.5 disco years back that did 450-500kms per tank and the local Landy specialist reckoned that it should get a comfortable 400kms per tank even around town.
I am fairly unfamiliar with the efi so he took it to the Landy guys who took a quick look under the bonnet and discovered that- a: the serpentine belt had been creatively routed and the water pump was running backwards, and b: several of the minor vacuum hoses had also been randomly fitted including the cruise control and fuel pressure regulator.
They fixed these and sold him some injector cleaner to put in the tank, but said that as it had probably been running with excessive fuel pressure for god knows how long, chances are the valves would be all carboned up and would probably be the cause of the intermittent misfire. Unfortunately their tweaks didn't help so we bit the bullet and I pulled the heads off. There was not massive amounts of carbon buildup on the valves but the valve seats were pretty poor so we had the valves ground. The reconditioner said it had 4 slightly bent valves!
All was reassembled, cleaned and tidied and the engine runs beautifully. Smoother with a bit more power and sounds great. However, the fuel economy is still exactly the same. :x He has brought it back in to work to tidy it up and prepare it for sale but I would really like to be able to fix it for him. He did casually mention when he brought it in that it doesn't actually shift into 4th gear 'til 80kph! I checked and found the kickdown cable to be overtightened by about half an inch so I fixed that but I don't know if that would be enough by itself for a vehicle that rarely sees the motorway in regular use.
I spent a bit of time fiddling with it this avo and put a colourtune plug in it which showed a perfect flame, also, it doesn't blow any smoke so I am fairly certain that the engine is not the issue but I'm running out of ideas.
Any thoughts, good people?