1988 760 Fuel pump runs briefly when turned to off

[TylerW71]

Hey guys:

I have been away from RWD Volvo's for several years, but recently rejoined the family with a 1988 760 turbo wagon.This was a nice but cheap and somewhat neglected CL purchase.

I have a fuel pump-related question. This 760 had sat under a carport for several months. We had to jump it off, and it started fairly easily. We backed it to the street, drove it to the trailer to load it, and let it idle while we put the ramps down.

After about a minute, it quit dead like the key was turned off. After that it never started again. Then, the starter also quit working, so I'm dealing with two issues at once.

Here's the evidence/question: When I turn the key to ON, I hear no fuel pump and no fuel pump relay click. However, when I cycle the key back to OFF, I hear a brief 1-2 second hum from below(where the pump is) and a click from the relay under the console.

Is this normal? This is the first 7XX I've ever owned and my learning curve so far has been STEEP. Thanks for any help.

[93Regina]

...fuel pump-related question.

If vehicle has a Bosch LH 2.2, then "On 2.2, the ECU provides the ground for the relay to turn on the fuel pumps. The ECU provides this ground only when it gets a signal from the spark computer upon engine rotation."

In other words, the engine must be rotating before fuel pump is engaged.

[TylerW71]

Thanks for the info. Everything seems fine other than it may have a dead transfer pump.