Sender pump Question
 

Picked up an immaculate '90 240 GL(40,000 miles).
Loses power occasionally enough to make it unreliable,marginally.
When the ignition is turned on, should you hear the pump in the fuel tank for a second or two?
When I disconnect the fuel line to the pump under the car and turn on the ignition,no fuel comes out.
Also when I hook up a gravity feed and run the car, nothing comes from the tank.
With everything hooked up normal,
the car runs fine, maybe a little bit shaky at idle,just a tiny bit.
But I have a '91 240 Est and when you turn on the ignition, the pump under the car also runs for a second.
On this '90 240, nothing happens 'till you start the car.
I've checked the voltage to the sender in the tank and I've got 6v rising when the car starts.
It's a shame not to be able to trust it.