We had a problem with the manifold pressure on a VM1000 a couple of years back.  It turned out to be the transducer, which was several hundred dollars to replace.  The transducer has a black plastic Sensor mounted to a printed circuit board.  The sensor is made by Honeywell part number SCX15AN.  We purchased it from Digikey (their Part No. 287-1023-ND) for $65.00.  It appears to be available from several sources for about $79.  You half to do a little desoldering and soldering but it worked out fine for us.

 

Tom Byrnes

Lancair IV N54TB