Completely stuffed

[marty hola]

hi new to the site! bit of problems with my truck the things been an absolute terror, everytime i fix it something else just breaks right away! im in to deep to get rid of it now just spent too much on it. now my problem. its a 1990 surf with a 2.8 turbo in it. the trucks had a tap in it since ive owned it never been a problem. now its pouring out black smoke when under load. it has a loud tap/knock i cant see where its coming from it seems like the top but its too hard to decipher exactly where it is. the pully at the bottom is loose also the one that drives the altenator but on the motor i can move it backwards and forwards. and it has a noticeable loss in power. it has a brand new head in it from lineside also. absolutely baffeld by this thing. the tapping noise sounded like a whine/screech wick eventually turned into a tap/knock

[tweake]

front pulley has failed.
need to check if its the balancer thats come apart allowing the outer part to slip or the whole pulley has come loose on the crank. both are fairly common.

the whole pulley come loose might explain the knocking sound. it can be a major depending on how badly damaged the crank is or just be a case pr replace the pulley and key. make sure you loctite the new one on.

[tweake]

as far as black smoke goes, what injection pump does it have?
what boost are you running?
could be lack of boost, pump, injectors or cam belt has slipped.

[marty hola]

so worth taking it to a mechanc? dont know what pump. boost is factory i have a free flow exhaust and it started playing up a day or two after i installed it.

[tweake]

can you post a photo of the pump?

does the exhaust sound louder than before?
if not you may have a restriction in it causing high back pressure.
or you have knocked something when you installed it.

[slide]

so worth taking it to a mechanic?

By the description- yes I would reccomend it.
Even tow it there.
My fear for you is that the damage may get worse if you run it trying to find the problem. If a trained ear has a listen, the diagnosis may be made within a few seconds as to whether the engine may need work that if left will cause serious failure. (eg a spun big end bearing can be fixed, a conrod out the side of the block not so).
How ever you best know your situatuion
Good luck
Nath