burnt spark plug problem.

[b16 mini]

hey people,
my mates been having a few issues with a misfire on his 98 ukdm dc2,i changed the ht leads and it seems to of made it better,but i also checked the plugs on the weekend and found that plug No 3 seemed slightly burnt up, the others looked fine, plug 3 also looked worse than the others when i changed them all about 8 months ago, so it would seem to me that cyl 3 is running slightly lean,
so i'm thinking it's probably a dodgy injector(seeing as its only 1 cylinder),
going to try to get the injectors flow tested, or may try some second hand injectors,
this is just a guess at what it may be, so if anyone else has got any other suggestions of what it may be or ideas of what else to check,???
would be greatfull for any input.
thanks

 

[civicsport]

check your dizzy cap and rota arm to see if they are scummed up. could try some injector cleaner.

 

[b16 mini]

dizzy cap and rotory arm are new, dont think that that would cause a burn't plug tbh,

 

[blinx9900]

cylinder number 3 is usually the first to start showing problems on a hurt motor i hope your right and its just an injector though...

 

[b16 mini]

cylinder number 3 is usually the first to start showing problems on a hurt motor i hope your right and its just an injector though...

it seems to be taken a fair few miles for the plug to get in the state its in, all other cylinders seem fine, seems a bit odd( in what way do you mean hurt??obviously its getting hotter on that cylinder, but what else could cause that?
hoping its nothing major like bore damaged or rings or valve related problems, it seems to run ok, and pulls well,
where do you recomend looking at first if its not injectors,?
a bad lead causing a bad spark wouldn't burn a plug would it?(
thanks,.

 

[woz5]

if it is running lean and if its just cylinder 3 then first of all check theres no air leaks to that cylinder ie cracked manifold port to cylinder 3 or leaky gasket round the cylinder 3 inlet area,if its definately all good then try swapping the cylinder 3 injector with another cylinder and recheck in say about 500 miles time, if you get the same results 've got your your problem,might just mean burning another spark plug though but its better to eliminate that before worrying about big stuff like piston rings or valves

 

[Kris!]

Cylinder No3 seems to be a weak point on the B-series and seems to get hotter than the other 3 cylinders, hence the plug getting slightly hotter than the rest. A mate of mines DC2 also has the same problem at present with plug No3, although his has started to use a fair bit of oil aswell now!

 

[b16 mini]

hmm, spark plugs are available singley, so may have to replace them and do some trial and error, thanks for the input.

 

[b16 mini]

hmm just thought it has a dc sports 4-1 manifold, and the tube on cyl 3 has been crushed a bit, wonder if that would contribute to the problem a bit... slower/restricted flow....bit of a far fetched idea but i do wonder lol