missfire\blacksmoke

[tenby05]

hi,right i was on my way home got to my street put my foot down in first to about 5k as i reversed on to my drive and cut out when i started it it sounded like it had a miss fire so i went to buy some plugs and leads, then went home to change them and got to the last one at the waterpump end and the new plug just sloted in without screwing up, then looked at the plug and it was a different size thread but wat pickeld me is that the numbers on the old plugs are all the same just one has bigger thread.

any help great thanks, peter.

also it puffs out black smoke when i try to rev it a bit.

[jox]

sounds like someone has previously threaded a spark plug and replaced with a bigger threated one.

as for black smoke turbo oil seals could be on the way out or valve stem seals, maby evern piston rings. do a compression test on the head

[owe]

the usual rule is white smoke water, blue smoke oil and black smoke unburnt fuel

[bernard]

check the old plugs an see if there covered in oil or somthing to stop them working as norm,remember Its all good changing the plugs etc but you have  got to get to the root of the problem I used to try everything with my rs turbo it was engine after engine sorry dont mean to put you on a downer could be just somthing simple

[Ash-Lee]

Black smoke = Overfuelling.

[tenby05]

my plugs were coverd with like blackdust it badly overfueling.

thanks guy,s could this only b the carb or something to do with the engine.