Volvo Repair: 91 Volvo 740GL phantom shutdown, fuel pump relay, inner fender

Question
My mother has a 91 volvo 740gl,she came to me complaining that it would "shutdown on her at times".I went and checked it out,it would crank up and run great,sit there and run for a while great.
I thought she was nuts,being concerned for her safety I drove it to my tire store the next day with out any problems,Looked it over with the little equipment a tire store would have to diagnose a driveablity problem,"nothing happened".
Upon driving it home a got about six blocks and it shut down,no warning,no shutter,just shut down.I tried to crank it right back up,it would spin but no go. I waited about 30 seconds and it fired up fine.When a bit more up the road and it cut off the same,with the same results.It's almost like an ignition relay is tripping.This has become a frustrating problem for me because It is an intermitant problem,and for a mechanic it make me look like a jackass that I can't fix my own mother's car,"especially one I recommed she buy".Please help me.

Answer
first I would check for diagnostic trouble codes.below is how to do so.if there are no codes I would try wiggling the speed sensor wire which is located between the cylider head and firewall on top of the transmission bellhousing and see if this makes it stall if it does then replace it.I would also try this with the ignition power stage  which is on the drivers inner fender beside the air cleaner housing.if it stalls when the wiring is moved replace it.also check the connection for the radio supression relay which is a black relay near the power steering resevoir.there may be 2 relays like this one is cooling fan other is radio supression relay.if you are handy with a soldering gun I would check the relays for bad solder joints and solder any that look cracked.look closely.I would also do this for the fuel pump relay.


CODES
in the engine bay on the drivers side near the strut tower there is a small black box with a wire attached to it.place the wire in the terminal marked 2.turn ignition key on (not started)press the small button for 1 second and the code will be displayed as a series of flashes.a red led displays the codes.the code will be three digits.small pause in between flashes for a single number long pause between flashes for the next number.example 121 will be flash.....flash..flash.....flash.repeat three times or until first code repeats itself.to erase the code after all codes have been checked hold the button for a good 5 seconds then release the light should light steady,then press for another 5seconds.this will erase the codes.  email me the codes and i will tell you what they are..socket 2is the fuel system 6 is ignition.


FUEL RELAY
the fuel pump relay is located on the fuse panel behind the ashtray.remove the ashtray and then remove trim around lighter socket then you will see 2 screws remove the screws and the storage area will come out the relay is white and about 1x3x2 inch.it will be towards the drivers side of the panel.