a friend of mine has a 1986 defender 90 with the N/A diesel lump in it.
anyway, after one of the pistons decided to part company with half it's skirt last year, it was rebuilt with new head, pistons, valves, rings etc (we didn't know about the 200tdi transplant route until 6 months later d'oh). all was running fine for about 9 months (apart from an issue with the cooling, gauge showing hot, but not boiling/pressurising or anything head gasket related as far as we could tell), until last November when it started to lose power then stopped completely.
I towed it back to his, where it has sat since, (he works away most of the time, so not been able to check it out properly till now) we had a look over the weekend, and this is what we found;
when it is cranked there is a very significant sucking noise through the air filter (could be blowing, didn't really check)
valve clearances have been checked, and they appear to be fine
sump has been removed to check underneath, nothing obvious under there, no lumps of metal in the sump
injectors have been changed for new ones (faulty injector was suggested by a local diesel mechanic who has 35+ years experience with diesels) but with no apparent difference noted
now when it is cranks, it tries to start, black smoke is visible from the exhaust, and it will just about run, but not on it's own for long.
we are going to check the timing this weekend coming to see if it has jumped at all, (anyone know what size the crank pulley bolt is?) and to change the belt as a matter of course.
are there any other areas we should be investigating before we go as far as whipping the head off?
all help muchly appreciated on this one, as he needs his truck back on the road for next week.
cheers all