black smoking exhaust and back pressure from breather

[toybota69]

hi there,i own a 1995 2.4 4x4 hilux pickup deisel and it has back pressure from the the engine breather pipe,it also is smoking a lot from from the exhaust {black},when going up inclines and fast aceleration,does any one now what is going on,i dont have a compression tester,are the rings worn or could it be passing valve guide seals,i am about to remove the head,and have a look see,check rings ,lap in valves fit new guide seals big ends and rings,it would be nice for some-one to give me some advice on wether i am doing the wright thing,many thanks mark

ps i run it on a gas mix {propane and deisel}and its even worse when i put the gas on,but i do get 45 mpg with it{on a run},have had the injestors tested and they are fine.thx mk

pps 160 k on engine but was poorly serviced before i bought it,sludge in oil.

Edited June 4, 2016 by toybota69
relevant imfo