Hello.
I've been having this issue since I bought the car a couple years ago. It doesn't really bother me but it might be an indication of a malfunctioning part.
The car sounds perfectly fine in idle. I have no leaking injector seals or intake leaks.
I have a known issue that I have still not fixed that is the swirl flaps actuator linkage is detached so swirl flaps are not working, I put them in the open position. Will do the swirl flaps delete mod in the near future. Anyway I don't think it is related to this issue.
But if you put the gear in P or N, then press on the accelerator pedal, it jumps to around 1200/1500 rpm and stays there for a while, after some time it goes back to 750rpm which is the normal idle speed. If you switch to R or D gear it will instantly go back to 750rpm. This only happens in 4Hi position, will work fine in 4Lo where it always goes back to 750rpm.
High idle video:
Normal idle when in 4Lo:
I have no relevant codes on engine or transmission.
I have no clue on what's happening. Found some people having the same problem on google but there wasn't any confirmed solution for it. You guys know what's happening? Might this indicate bad fuel regulator or fuel pressure sensor?