Two possible causes, Newps...
One is a broken wire(s) going to the instrument panel where moving the wire
around to work on the lugs causes the broken ends to abrade and make better
contact for a while, and then they reoxidize... This is high on my
suspicion list since it is the same two wire runs all the time.. Don't take
the lugs apart this time, simply give the wires a good workout and moving
around and see if that changes it..

If not, then the surface of your terminal lugs (stake on rings) are
oxidizing... If your hardware for the lugs does not have those little
stainless, star washers, get them... Now, they do not go under the nut
(which we are all conditioned to do), rather they go between the lugs of the
two wires so that the sharp edges of the stars bite into the metal of both
lugs as you tighten the screw, maintaining a gas/oxide free contact between
the two lugs.. We are working with a few millivolts of signal, and it takes
almost no oxide at all to act as a resistor and block current flow...

Not sure what you mean't by 80 and 250 for EGT, so I suspect a typo...

Denny

"Newps" wrote in message
news:x7L2b.200219$cF.66312@rwcrnsc53...
I have the Electronics US8A, which is a 14 channel EGT/CHT. My problem
is with two of the EGT temps. What happens is my number 2 and number 4
cylinder report EGT's of between approx 80F and 250F. They dance all
over the place. Very rarely will the EGT be right. Now, if I take apart
the two connections for each probe and spray them with carb or brake
cleaner they will work properly for about 2 hours, then I will go back
to the same problem. So it seems to me the electrical connection in one
or both of the connectors is intermittant. Any ideas? I did buy a new
probe and installed that but that doesn't change the problem.