Car is hunting as if there's not enough fuel

[curtisg40]

Started the G up this morning and the car was hunting really badly as if there wasn't enough fuel but I have a quarter of a tank, I once had this problem but it was when I drove over a really high drain and a blue cable came out of the clips underneath but I've checked that and it's all ok , can anyone shed any light to my dilemma.

Thanks

[Jezza-7]

unplug your blue water temp sensor then see how it runs.

[Boris]

Check for vacuum leaks

[curtisg40]

I've tried both those and still no difference I also found black soot comin out of the exhaust
Any ideas?

[Jezza-7]

Maybe your lambda sensor?

[grayg40]

fried piston, thats what mine did a couple years ago and it idled over 1k. but could be some of the above posts.