New member here plus questions.

[Jerkwaad]

Hello fellow enthusiasts.
I am brand new to this community. I am 21 years old and from the Faroe Islands. I share your interests for older vehicles and vintage diesels.

My Volvo Story + Questions:

In august 2009 I bought a 1987 740 gasser (b230e). It's rusted out on the meadow now. I just use interchangeable parts of it, for my 1986 turbodiesel 760, which I bought in october 2010. When I picked it up, it barely started and smoked heavily white. As winter approached, it wouldn't start without lots (intermittent sprays) of ether. I then ordered a 1991 d24t replacement motor from Denmark. In the beginning of 2011 I had it installed, but it wouldn't keep running. If I primed the pump, it would run until the pump was empty. I couldn't believe the lift pump was leaking, so I put the project on hold, but removed the injector pump from the original motor before I threw it away, just in case I decided to try and replace it. (By now I do know, that it was a very bad decision to scrap the old motor though).
Sure enough. Last year I replaced the injector pump, and it fired right up and has run ever since.
I have removed the cold start device and added a cable in its place. According to a section of a manual I found online, my timing is supposed to be set at .75. I so did, but as the timing advance is so low, it idles very roughly, misses a few fires and bounces and smokes black, when cold started, if I don't pull the manual advance lever. When she is warm, she runs great without the advance lever actuated. Is it in any way bad for the engine, to let her run cold on .75 timing advance, and low rpm?
Oil pressure is great instantly when cold and she has NO blow by, but when she is fully warmed up, the oil pressure gauge goes all the way down to the red zone and she obtains a bit of blow by too. I am running 10 w 40 oil in it. Has anyone ever experienced this? I have the stock oil cooler at the filter lip. Do you assume the coolant flow in the oil cooler is clogged or should I switch the oil to a different viscosity one?

A scary story:

Through this winter, I have been rewelding the car's rusted floor in the garage. I took her out again about 20 days ago. I rushed her cold up a long hill and pushed her. Suddenly I recognized she had fully overheated. I immediately swithced off (even though the turbo could die) and went to check. There wasn't a drop of coolant in the system. She had leaked it all out, through a leak in the lower main hose flange, throughout the winter. I let her cool off to moderate temperature and drove her home carefully, keeping a steady eye on the temp gauge.
As the cylinder head is long, narrow and made of aluminum alloy, I would expect it to warp easily or crack. However. She still starts perfectly when cold and has no white smoke when hot and NO water in the sump. I seemingly got lucky, because she is just as she was before. She has never idled 100% smooth and you can feel the motor jerk a little bit when inside the car, like in a big truck. I assume this could ether be due to insufficient bucket adjustment or not perfect cam timing.
I am pleased to be in this forum now, and must say it's impressive to read some of your detailed knowledge about these engines. I will post a video to youtube and link it in here sometime. Take care mens!

Sincerely Ragnar W. Eliansson.