2000 td42t surging

[AngusTD]

Hello I'm new to this forum, my 2000 td42t ute surges past 2k rpm on light throttle but when I plant it, it doesn't surge. I'm pretty sure it also blows blue smoke, I can't remember (last drove it today &#128514 anyways id appreciate any suggestions, thanks

[AngusTD]

Another update, just found out it only happens when my throttle is at a certain point maybe like 5 to 10 percent