Just got my mk1 1.6td, turned in the max fuel screw a bit, just enough to where it smokes enough to see it well

, had to turn down the idle, but ever since ive got it, I noticed that after givin er some gas the revs are slow to come down, and last night i did a 3rd gear pull, and when i let off the revs just stayed high for too long, so i put it in 5th and brought them down myself and then it idled, maybe my throttle springs need lubed? Have no idea!