What is this problem?

[NovaBoi92]

My friend has a 1.4 puma. He was driving along yesterday and the engine stalled, and when he started it back up it run very lumpy and chucked out loads of grey/white smoke. What could cause this? I'm thinking head gaskit maybe, but havent had a look over the car at all yet.

Constantly running lumpy with excessive smoke

[General Baxter]

has it been swimming ?

[shrtwrec20]

sounds like water getting in where it shouldn't be.
Either on the plugs or in the ignition chamber.
Also if it's running lumpy could be air getting in through a weathered/damaged hose or inlet manifold gasket etc. I guess the list could go on :(