running lumpy, tapping, and no power

right 300 disco, fine when i bought it, then i turned the torx on the inj pump up a bit as you do !, then a week later lift pump went, when pulling this out if ound the arm wasnt connected :0..... took sump off, no sign of it, in the lift pump slot or bottom end, so i became brave and bought a new lift pump, fitted it, and no real worries, about a week ago i thought car was a little down on power, may have been after drving td5 for a week, but yeh so i followed the tuning post and tuned the old girl up,... i have been running it on engine oil mix 20%..... but for last 100L it has been white derv diesel, but still smoking like a train..... when i put my hand over exhaust it coughs a load of sutt into hand, there is a light ticking noise going on but not sure where from...... theres oil all down the head, and some ontop of the manifolds
my following thoughts are
head gasket-checked back no gasses, no oil in water etc
turbo- not chekced how ????
blocked injectors ? not sure either
valvle stem seal ??? not sure
injector pump boloxed ? not sure how to tell
vaccum pump making noise or lift pump or inj pump

can any one shead any light on why the noise would be there, why its down on power and its pretty **** on fuel too ?????

When was the last time you swapped the fuel filter? Disco of fender? Disco has a sedimenter thing in the rear wheel arch I belive

Oil on the head? Maybe blown inlet gasket causing it to loose boost pressure

took head off as iv got two weeks of school, turns out its missing a bolt in the inlet manifold so that was blowing, there was that much **** around the injectors that diesel must have only been coming out of one pin hole per injector ! going to re lap the valves and put it together today, not to shabby apart from that

if anyone has info on doing tappets id be happy to hear it

Use the 9 method set to 0.20mm

Make sure the little caps resting on each valve stem is present and not damaged.
Undo locknut then back screw right off and you will be able to remove the cap with fingers to clean and check. (LJC100270) Number for replacement caps

No.3 tappet with No.6 valve fully open.
No.5 tappet with No.4 valve fully open.
No.2 tappet with No.7 valve fully open.
No.8 tappet with No.1 valve fully open.
No.6 tappet with No.3 valve fully open.
No.4 tappet with No.5 valve fully open.
No.7 tappet with No.2 valve fully open.

Rocker gasket ERR2409

James