Volvo Repair: 1991 Volvo 740 fuel delivery, fuel pump relay, accelerator pedal

Question
We have had trouble with the fuel pump quitting while driving at various speeds. Each time the car will restart after sitting for anywhere from five minutes to as much as overnight. When the problem occurs and upon trying to restart the car the single in-tank fuel pump does not run to bring the pressure up as it normally does (normally hear it for about a second or two). When it does restart the pump can again be heard before start-up. Have replaced both the system relay (fuel pump relay) and the auxilary relay (injector relay) and the problem persists. What other components feed into the system. Are there potential week points for power getting to the fuel pump or that would cause the fuel pump to suddenly cut out but then restart after sitting? I don't know if one other problem we are having could be related but upon cold startup we have to let the engine idle for a minute or so, or the engine will die, no matter how fast or slowly('feathering it') we try to depress the accelerator pedal. Is there a way to check the electric draw on the pump and a way to trace the fault when the pump is not running. Nothing shows up on the diagnostic box under the hood when we check for fault codes. We would very much appreciate your help. Thanks Jeff S.
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Answer
it is possible the fuel pump is not working intermitently.the other problem could be a bad control unit not giving a ground signal to the fuel pump relay.the only way to be sure is to test with a test light.for ground to relasy and power out of relay to the pump.