...all four have heavy dry sooty deposits on them, i cant remember how old they are, possibly 2 years old. its done 20000 miles since new piston rings and stem seals, 10000 miles since new turbo and a new grpa headgasket 1000 miles ago due to manifold studs snapping.it ran well with a puff of smoke on over run but nothing ott. what should i be looking at in general order of likely causes?

 

id say they are just due a change fuzzy ,may be running a bit on the rich side


cheers james

 

whats the fuelling like? does sound rich

 

ive no idea about things like fueling. i break it someone else mends it. im selling my engine to someone wanting a complete drop in conversion kit for another e30 and i dont want to let it go just now if theres a possiblity that something negative might come back. unfortunately its almost removed from my e30 so i cant run it just now.
all the plugs are the same condition and this is a random pic of the 3 plug from the front, im not sure if it tells you much but it does give an idea of how sooty they are....

 

Spark plug condition is really only accurate for the recent driving condition ie. if its been sitting at idle for a while they will most likely show up rich even though the car could be running lean at full chat. It can really only be used as a rough indicator.

JAmes.

 

so realistically it can be as simple as needing a tune up to sort the mixture?
is it james day today? everyone thats replied is called james and by coincidence so am i

 

yeah, it will be a mixture issue if anything,