Hey everybody, thanks again for the help with my wife's 1993 240 Classic wagon back in thread: http://www.brickboard.com/RWD/index.htm?id=1579953&show_all=1
However, the problem still seems to persist from time to time. The car is fine for a week, and then dead with no-start condition and requires a tow home. In this condition, the car can be started on starting-fluid/ether, so I know it's a fuel delivery issue.

My hypothesis is this, there's a poor wiring connection somewhere for the main fuel pump, and possibly/probably the ground. When there's no pressure load on the system, and the pump is only drawing an amp or two, everything works fine and the flow is good. However, when the pump has to do work (pushing against the pressure regulator), and it's trying to draw a regular current load, the resistance of the connection(s) goes up and the pump voltage drops and browns out. I haven't proven any of this yet as I'm trying to minimize laying in the snow under the car unnecessarily. I've cleaned almost all the ground connections during this project earlier, but I think I missed the main fuel pump. All of my Volvo green manuals are buried in the storage unit and I'm hoping someone can tell me where the fuel pump ground is located so I have the dismantle the least amount of seating and carpet to get to it. I do have my Bentley book and the wiring diagram does not show specific locations for this circuit.

Thanks for the help in advance and God bless,
Fitz Fitzgerald.

P.S. For any of you studying or considering pursuing an ASE Automotive Mechanic's certification, one of the test questions you'll have in the electrical section pertains directly to the situation above. It might be phrased like "What is the likely culprit if a tail & brake bulb glows with the parking lights on, but completely dies when the brake pedal is pressed." The answer would be something like: "A poor ground connection at the bulb or in the wiring has a resistance increase when additional current is applied and opens the circuit."