Fluctuating Idle on Gen 3

Hi guys,

I have a 2001 Jimny which generally seems to run ok - I only recently got it so don't have a great idea on the history but I've noticed that the idle revs are around 1200rpm but after a few mins of driving (approx 10-15 mins) I notice the idle revs creep up to about 2000rpm before dropping back to ~1300 and then back up to 2000rpm etc.

Has anyone got any idea what might be causing this? I recently did an oil service, spark plug, air filter change but it still seems to be doing it.

Any help would be appreciated!!

Thanks in advance!

It does it on its own, but only seems to do it after the car has been running for 10-15 mins. It can be sat idling at ~1200 before climbing to 2000rpm in about 2 or 3 seconds. I don't need to push the accelerator to get the revs to creep up to ~2000, it just does it on its own after the engine is warmed up. It then drops to around 1200/1300 (this happens pretty much instantly after it hits ~2000 i.e. it doesn't slowly drop back down) before creeping up to 2000 again, then back down and so on...

What I have also noticed (might be unrelated) is that the accelerator pedal sometimes seems 'sticky' when pressed down for the first time - like you have to unstick it if is hasn't been used but then after that it seems ok (until next time you drive the car).

Again, thanks for the suggestions above, if any other info would help diagnose then let me know

Cheers