Volvo: 1981 volvo 240 cold start issue, engine cranks, flame trap

Question
Hi, i have an 81 240 that has had a cold start problem for quite some time.  I've aquired the records from the previous owner, and in the past year it's had a warm-up regulartor replaced, injector seals, throttle plug, plug wires, plugs, flame trap, and such, it appear in attempt to alleviate the cold-start issue.  One mechanics report claims the cold-start fuel pressure was measured at 42psi, when it should be 15.  Since i've owned the car, i have replaced the fuel filter, and removed the flame trap, which had allready clogged up again.  The car seems to not be getting fuel until it's been cranked for a good 10-15 seconds, at 3-5 second intervals.  Once it's been started, and run even for just a minute, it will start fine for the next 6-8 hours.  But after that the same problem occurs.  I noticed in the records that owners of the car have been trying to solve this problem for almost 5 years.  I'm wondering if you have any ideas.  I have the full dealer service manuals for this car, and have done various small jobs on my volvos, like seal replacements, water-pumps, etc., but i am definately not an expert mechanic....

Answer
Darren,
There is a check valve in the fuel pump that holds fuel in the line so it will not bleed back to the tank. Maybe that failed. You need a set of fuel pressure test gauges, check the line pressure that should be about 65 psi. Test the running control pressure 50 psi. Leave the gauge in position two turn off the engine see if the pressure drops to below 15 psi in 30 minutes. If you loose rest pressure start with a replacement check valve. Also test the in tank pump to be sure that is working when the engine cranks. Get you book out for the fuel system and follow that fault tracing. The Bosch system is kind of diffcult, you would need maybe to find a shop that has an older tech that remembers the system and has the proper gauges and some good old books. The infor that I have does not go that far back.
So to review, the gauge hooks to the control press regulator larger fitting and the hose back to the gauge. Center position of the gauge is position 2 that should read about cold 1.7 bar to 3.5 hot. Control pressure should not go any higher if it does the Control pressure regulator is bad. Line pressure position 1 handle toward the fuel dist should be 4.5 to 5.2 bar line pressure. Position 2 engine off tests rest pressure. It should not leak down lower that 1 bar. The places that leak are the injectors, check valve, fuel dist. The pressure I quoted should be close since I;m doing them from memory. My old books are all misplaced.