Volvo Repair: 98 Volvo v70, mass air sensor, volvo v70

Question
QUESTION: My 98 Volvo V70 will intermittently stall.  It does not matter what speed or load.  It quits for about 2 seconds then recovers.  It has been doing this for the last year.  Happens maybe once per hour.

ANSWER:   William other than checking the basics, you need to have it set a Diagnostic Trouble Code before you can narrow things down. Is the check engine light on?
  The only other way to proceed is with test equipment connected to your best guess culprit. Typically brief intermittent stalls are ignition system related. If all that checks out, start watching the injector waveforms. If you can catch it during an incident, you can pull a movie to review when you get stopped. those are the two most likely systems to cause this problem. HTH


Mark

---------- FOLLOW-UP ----------

QUESTION: The check engine light is on.  The code displays emissions leak (large).  I have replaced a valve that was recommended and checked all hoses from front to back.  No luck.  If the car would stall and not restart, then I could check for spark.  The car always starts right back up.  The intermittant and total start aspect of this leads me away from ignition and injector.  Coils usually just quit.  Wires, injectors would cause rough idle.  The car always idles perfectly.  It stalls as if the vacuum system was suddenly opened then closed.  Not sure what valve would cause this. Any ideas.  Some internet searches have suggested Mass air sensor/valve.  Would think that this would just cause rough idle.

Answer
  William, here we go now. "The code displays emissions leak (large)" and this "It stalls as if the vacuum system was suddenly opened then closed."
   That's what's got to be going on. I'm just trying to think other than EGR what could cause an instantaeous leak large enough to cause a stall. Check the purge canister for cracks or breakage. Also test the purge valve. I suspect you have a broken canister.

Mark