1999 s80 2.9 non turbo. Here is what I do have, spark, fuel at the rail (i can hear pump prime also), car turns over (tach doesn't jump), battery voltage fine, belt and cam sprockets are turning. For the past month or so the car would randomly start up and run real rough and then clear out. Anybody got any ideas on things to check?

 

Check your maf sensor.

 

how am I going to check it? just unplug it and see if it starts?