Resurrecting on old thread, but I just recovered from a similar situation with my Volvo injector pump. I got lucky though, as my pump was a little easier to work on than Hartley's. My symtoms were:
Engine fires right off then slowly dies. Takes extended cranking to get engine to start. Our small pressure pump to our diesel heater was also losing it's prime. I suspected that we were losing our prime to the injector pump. Further examination showed that the top of the pump was wet with fuel after these hard starts, but hardly any fuel leaking while the engine ran. I think the combination of foamy fuel in the injector pump body was the cause of the fuel leaks on starts. Rather than pull out the whole pump, which had a linkage that I didn't have good access to, I decided to try and repair the leak with the pump in the boat. I consulted with a Bosch Dealer nearby who said it was common for these old pumps to start leaking.
I ordered the O-rings and some copper washers to see if I could fix the problem without removing the whole pump. They are numbers 18 and 15 in the parts diagram
Scrubbed top of injector pump with WD-40 and a tooth brush to clean it up. Removed fuel supply line to top of injector pump (17mm wrench). Removed injector lines off injectors and injector pump (17mm wrench) Removed fuel return line (10mm wrench), Remove oil filler cap assembly (it was in the way). Shove paper towel down the hole uncovered by the oil filler cap to keep crap from gettin' in the gears.
Remove a little keeper dealy-bob between two of the injector delivery nozzle caps. I think this dealy-bob keeps the center cap from turning when you're pulling off the injector lines because you can't get a wrench on it to hold it. 19mm deep well socket to remove each fuel delivery valve cap. There is a spring under there, but it doesn't go boing when you pull the cap. Under the cap is the O-ring and a copper gasket that needs to be replaced. Here is a parts diagram. Takes about 1.5 hours to disassemble and clean. Takes about an hour to put it back together.
Put it together this morning and it fired right up. No leaks. Hurray, we're going out to Hope Island to enjoy this weather while it lasts.