Tried on two occasions with 2 different sets of sparkplugs and my car will not run on em. Tried just now with a new set of NGK plugs and with all 4 in it just sounded like air sucking through then would just about fire up then run itself dead immediately and sounded terrible.

Tried changing plug by plug for all 4 and eventually eded up all 4 old plugs back in. Now runs but sounds like a tin full of nails rattling around.

It's a mk2 1.6 petrol engine. Old plugs are prob 2/3 years old but that's all the fussy cunt will run on, and now not very well.

Help please as I do 50+ miles a day in the sodding car.