'89 240.... occasional loss of power

one of the problems I've had with my 240 wagon since buying it 3 years ago
has been occasional episodes of loss of power. Generally, it runs great, but
sometimes there's just nothing there, the engine stumbles, no acceleration,
etc. The only thing I've found that fixes it is to pull over, shut the
engine off, pop the hood, and work the connector to the Mass Air Sensor on
and off several times. When I restart, the car is ok again. The problem
occurs at random (hot, cold engine, warm, cold, wet, dry day, first startup
of the day or after several stops for errands). The plugs and plug wires are
new, Air filter replaced every other oil change, Flame trap cleaned
regularly, along with checking vacuum hoses. The fuel pumps and filter were
replaced (probably unnecessarily) a little over a year ago. The connector to
the Air Mass Sensor seems to be free of corrosion, and I've cleaned the
contacts with some PRO-GOLD contact treatment. The "fix" can last hours,
days, even weeks, but the problem returns... any other thoughts?

m9876c at yahoo dot com

 

Perhaps cracked solder joints within the air mass meter itself? The fact
that fiddling with the connector seems to fix it for a while suggests
something in the vicinity, or perhaps it's just a coincidence and having the
engine off for a moment is what fixes it.

 

sounds like a new air mass sensor might be in order!... Could also be the
harness, although the wires look to be in good shape, no obvious wear or
strain.....

any idea if the sensor can be opened to resolder? My guess is that it's a
sealed unit, and probably not cheap!

 

I think it can be opened actually, I'm about to find out as I have a dead
one sitting out in the garage. I can verify though that it isn't cheap, it's
about $500 from the dealer, but I've seen remanufactured units for around
$250. I usually buy them when I find them at junkyards for $20.