Volvo Repair: Volvo 240 trouble starting, flash flash flash, example 121

Question
I have a 1989 Volvo 240 GLE that has been showing signs of starting trouble. It usually starts right up in the morning and when it's been sitting but if I stop it to run into a store it often has trouble. It has only done this about four times in a two month period but the incidents are getting more frequent. Often it will start after giving it a few minutes but this morning it just simply refused. It will crank but doesn't seem to catch. I have had a new oxygen sensor installed this year and was told I will probably need a new clutch in the near future but this does not seem related. Could this be something with the fuel line and is there anything I can do to treat it without it being outrageously expensive?

Answer
I would start with checking for diagnostic trouble codes in the fuel and ignition systems.below is how to do so.



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.