It will rev high for about 10 seconds and then go back to normal, as if the throttle is sticking? That happens every time I get out of a gear, its a stick btw.

 

It could be sticking, you can clean inside the throttle butterfly with carb cleaner. Or cable could be bound up and need lube.

The Throttle Position sensor tells the ECU the angle of the throttle plate, and based on the return of that angle to minimum position the ECU shuts down fuel to injectors and prepares for idle speed. TPS might also be gunked up, but clean with electrical cleaner, too many small plastic parts. Once at idle, the IACV controls idle (a 200 position steper motor or computer controlled vacuum leak). The IACV can be removed and cleaned with carb cleaner, but don't move the end of it, let the computer do that.

A code reader scanner can display throttle position, it should be 9-10% at idle, it actually should not be at zero. You should see a smooth transition of values, not huge jumps, as accelerator is depressed. It is a potentiometer, fancy word for "volume control". When electrically dirty will make "static" just like an old radio. ECUs do not like "static" and computations are frazzled.

Pages from shop manual attached.

 

I checked the actual butterfly and throttle cable and thats fine. Ill check the other stuff tomorrow, the problem is this:

I start the car and it jumps to 3k rpm, sit there for a while or until i give it a little gas then it drops to 2k and sits at idle at 2k, then I go to press the clutch in, it will jump to 3k and when I put it in gear, it will go to normal, as soon as it take it out of gear and press the clutch in again, it jumps back to 3k, pretty much, it sits at 2k idle

 

ATTN MODS: this is NOT for a discovery II, this is for my newly bought 96 DISCO, please move back to DISCO 1

 

Sounds like IACV and/or vacuum leak. Can also be engine coolant sensor telling the ECU that it is -40F out there. If you have a code reader scanner, or can rent one at parts store, check for coolant temp. Should be garage temp at start up in morning. A D1 has two coolant temp sensors, one runs the gauge, a second one just talks to the ECU. Could be as simple as coolant sensor unplugged (it has a square brown plug on top - two conductors, gauge on on has single conductor) - near thermostat housing.

 

 

I've noticed that when I had a vacuum leak, mine was at the SAI pump, but you may not have that feature.