my volvo pretty much just quit running one day, like it was running out of gas but i put some in it and nothing. the guy i bought it from suggested a wiring harness

 

wranglerwheeler, have you checked fuses, spark, codes? Will it start,crank? I am going through the same thing with my 740 now maybe I can help you narrow it down,fuses are easiest. Turn key to run pos.(do not start) do you hear the fuel pump run?

 

Ok well an engine needs 3 things to run, air, gas and spark. You can check to see if its getting gas by unscrewing one of the injectors and watching it while cranking the engine over. Gas should squirt out. You can check for spark by taking out one of the spark plugs and holding it about 1/4 inch away from the engine block or some other piece of grounded metal and the cranking the engine over. You should be able to see it sparking (i like to wear a leather glove when holding the plug so I dont get shocked). To make sure you're getting air check to make sure the filter isnt really plugged and maybe check to see if the hose to the intake manifold is plugged. Figure out which one is the culprit and if you post back i can help you from there.

 

i changed the ignition wires and my dad jumped it off. he said it ran and hes driven it around some. when i changed them one pretty much fell apart in my hand