Cleaned Engine now slight stall coming to halt

Cleaned the engine bay a few days ago, wasnt keen on the idea
but it was bad.
Was gentle I thought with very light hose pressure but now the car starts ok and drives fine but just when Im coming to a junction in second it takes a shudder to itself as if going to stall so I press the clutch and it then idles fine. It pulls away and sits fine on motorway but when the accelerator is released and its just coming to a halt there comes the shudder as if a cylinder is missing. Im of the opinion Ive put water in somewhere, but why the anomaly of a light shudder. I thought it should have dried out by now.
Any clues.....Frank

sorry this post was a waste of time, I realise that I adjusted the handbrake at the same time as cleaning the engine bay and it must have been catching. wound it off and alls ok

Phew.