Advice needed 1994 Disco 3.9 V8

[mapeart]

Hi, I just bought a 1994 3.9 V8 Disco. When pulling up to a stop the engine stays revving at around 1500-2000 rpm for about 10 seconds, sometimes a bit longer. If I´m rolling along in neutral it doesn´t go down until about 10-15 seconds after I halt completely, then the revs to go down to about 800-900. Is this normal? It seems that it is burning a lot of fuel. Could this be a sensor or something?
Also, I am being offered a 200TDi and 300TDi. Are either of these a strait swap onto the gearbox instead of the V8 or would I have to change the box or something else?

Cheers,

Mick

[v8jobster]

it could be that the idle control valve at the back of the plenum chamber needs a good clean, i used carb cleaner, worked a treat!

As for engine swop, what gearbox is on your disco at present? From what i recall the auto box's from a tdi to a v8 are no interchangable, the ratio's are slightly different. Give someone like Ashcroft transmissions a call, they will be able to confirm for you.

[mapeart]

OK, sorry for being thick, but where is the plenum chamber located?
The gearbox is manual.
Cheers,

M

[discool]

OK, sorry for being thick, but where is the plenum chamber located?
The gearbox is manual.
Cheers,

M

On top of the engine with 3.9 on it.

[JulesV8]

Discool,

Is that a pic of YOUR enigne bay? HOW CLEAN IS THAT!
Nice work.

also, might be worth checking your plugs as this might be a reason for high fuel consumption. Other question...when was the last time you changed the air filter. The v8's like to breathe and do suffer badly when it gets mucky.

Hope you get in fixed.

J

[Devon-Rover]

Ditto above. Give the Idle stepper motor a good clean. they have been know to gum up a bit causing the idle to go askew.

As for the Fuel consumption then the only way to tell is to go out and properly measure how much you are using. Then if it is hideous then maybe a good service and a check that everything is in time can work well.