Car struggling to start some times 04 v8

I've seen this few times, in most cases it was the MAF, the CKP should make the MIL flicker or stay on and the CPS would give different symptoms, though with a LR nothing is ever certain:) and there could be many other reasons ... as said reading fault codes might reveal things

I gave my 4L a good rev once and blew the head gasket between cylinders,,
ran afterwoods,, just with this strange knocking noise---
hmm, knocking...