I have a '99 Series One Discovery w/173K on it. Last week the truck started a high idle thing. I have read the other High Idle threads, but my situation seems unique. Bascially if you start it, it goes to a high idle, but you can kick it down right away. Then once you drive it up past about 1500rpm, it stays around 1000rpm when in gear, and around 1500rpm when in neutral. I can ALWAYS kick it down by jamming on the gas pedal, whether it's in gear or in neutral. However as soon as I get it up above 1500rpm, the same thing happens, every time. So I find myself having to kick it down about 15 times on the way to work.

Any ideas?

Thanks!