Mx5 Fluctuating Idle, Shuddering between 1000-2000 RPMS

[zc32s]

So last Monday I completed a timing belt and waterpump change. I think everything went well.
Saturday I advanced the timing to 14 degrees.
Sunday I took it out for a spirited run and it drove really nicely.
Yesterday I cleaned the base of the windscreen because it was really dirty, i sprayed it down with a hose but made sure no water got onto the engine.
I also had to tighten the coilpack a little bit, I noticed the screws we're getting loose.
Then today I went to drive the car, it turned on like usual. I reversed it out of my driveway like usual, but when I went take off, it felt like it wanted to stall. I drove it around a bit more and noticed the engine starts to shake alot between 1000-2000 rpms.
I drove home and popped the hood up and I can see the engine idle smoothly then shake and it constantly does this

Anyone have any idea where I should start?

[93_Clubman]

1997 NA8?
If no water got into the spark plug wells then it sounds like you might have inadvertantly caused a poor connection somewhere during the recent work. May be even an old plug lead got damaged. Another possibility might be coilpack wiring loom which was an issue on the NB8A the following year. Move it around while running to see if it affects idle as the wires can break internally on the NB8A due to poor support near the coilpack.