engine shake

[wato]

Hello all,

            This problem on my 2007 is250 has happened only a couple of times the last 12 months. I stop for whatever reason, with foot on the brake and the car in drive and after a few seconds i get a bit of a shake from the engine as if it its going to stall, similar if a spark plug lead was disconnected. if i put it in neutral it idles normally, or goes back to running normal  once i start moving again. Only a spasmodic problem, otherwise car runs perfectly at other times. Many thanks for any suggestions

[Tony1234]

I'd recommend an upper cylinder and throttle body clean.Easy to do.

[wato]

thanks ill look into it