5KTQ rpm sensor failure

[Jeff & Debi <jplewis@cats.ucsc.edu>]

My 86 5KTQ with only 100k on it, just up and quit one morning on the
freeway. I bentleyized myself till my brain fried. No error codes
(4444).output diagnostic also ok. Had it owed to my mechanic.He finally
replaced the RPM sensor, it started right up, and drove 20+ miles. He
then put it in his shop overnight. the next morning, no start again.
What could be causing the RPM sensor to burn out like that? The car runs
perfectly (when it runs). I have "the knob" on it, But I removed it
until I get this problem fixed. Any help would be appreciated.

 Thanks in advance
 currently not subbed, but I watch the archives daily.
 Jeff Lewis 
 Aptos ca.      86 5KTQ less, and it's raining alot, I miss it.