Volvo Repair: engin wont stay running, flash flash flash, example 121

Question
I have a 1990, 740. it will turn over but can't figure why it won't stay running.  we got it restarted yesterday after it stoped, but now we can't get it to stay running. the fule line was checked and fule is getting threw.  

Answer
try checking codes first below is how to do so





n 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.