[urq] URQ quirqiness

[DGraber460 at aol.com]

My 83 is still being a bit of a puzzle. That's the nicest way I can put  it.
Symptoms: Frequency Valve operation comes and goes _very_  sporadically.
 
Actions so far:
New hall sender
New O2 sensor
new wire from ECU to FV
3 different FV
3 different (and verified) temp sensors
3 different flywheel sensors
3 different ECU's
Air temp sensor readings within spec
replaced fuel pump
 
For my money, that pretty much covers the bases. No amount of wire wiggling  
(including the back of the fuse panel) will re-produce or stop the effect.
Where do I go from here?
TIA
 
Dennis
Denver