I have a fairly new Subaru engine conversion in my van.  The engine itself
is basically new by way of an overhaul. It has 800 miles on it now. The
carrier bearings are a bit worn and they wobble sufficiently at 70 mph as
to cause the VSS to get erroneous signals which in turn causes the engine
to jerk like misfire or improper or inadequate fuel mixture. The carrier
bearing problem will be fixed next week. IF I keep speed below 70 then no
problem. However in ranges between 55 and 65 the engine will sometimes
suddenly shut off as if Ihave turned off the ignition. If I keep my foot on
the gas pedal then the van continues to slow down. If Ilet of the pedal a
few seconds the engine picks up and continues on its merry way.

Anyone have any idea what could cause this?