WHen I first joined this forum, I noticed my tach was never really happy anywhere above 5k. I quickly determined that it was in fact the tach that was not happy, rather than the engine. Today, it was the first really hot day out, and after being in the sun all day and then getting stuck in traffic, I noticed my tack was hovering around 4k. Which in itself is not that unusual, but I was idling at a stop light. I noticed it then began to bounce slowly back and forth as it made it way to peg the needle past 8k. Now since I was at idle, I was pretty sure that this was not really happening :stupid:. The car ran just fine, so I was really not worried, figured the tach was just borked. Now when I got it home I turned off the key and it immediately flopped back to zero. Flopped is pretty much the right word. When I turned the key back on, but did not start the engine, it slowly rose to peg the tach again. I went inside to mill it over. I went back outside in the garage after grabbing some water and fired her up again, about 10 minutes had passed. The tach was working. Ahhhhh Haaaaaa the plot thickens! I think this has the signs of a tach thats on its last legs. THe thing is though when it operates its dead smooth and pretty accurate. Well up to about the 5500 rpm area anyway. So, my question, is, could this be just a bad connection somewhere, or is the fact that the heat may have caused this just a sign that the tachs internal electronics are just too old and somewhere the Ohm (ie resistance) load is way to high. Or it could be short...So........... I am going to start by cleaning off the terminal ends around the coil and resistor on the firewall. Then I will look for any frayed wiring. I have an extra tach in the box I can replace it with, but the thought of pulling my tach back through my full dash cap is less than exciting... THanks for any answers..