There was a short screw in there already (I want to say it was used for motor mounts way back when but isn't used for anything anymore...maybe). So i just used a longer screw to hold the rod, then replaced it w/ the original short screw when i was complete. I would be happy if this was caused by something i did that was that dumb. Not that i haven't done dumber things in the past....

 

I can't agree with this recommendation... I too am using a Summit 1 1/2" diameter fuel pressure gauge just under the hood overhang and out of the driver compartment. Originally I had problems with this liquid-filled fuel pressure on a corvette drag race car. Although I typically set the fuel pressure to 7 psi on a cold engine for my Holley carburetor, at the track I found that it would show a lower pressure of 3 or 4 psi causing me to re-adjust the regulator. The next day, I would find the pressure higher at about 9 or 10 psi (cold engine).

After thinking about it, this liquid-filled gauge is sealed to prevent loss of liquid, but the air internal to the gauge will heat during engine operation and will see higher temperatures between runs. Since the air can't expand without a vent, the pressure within the gauge goes up, and because the bourdon tube within the gauge expands based on differential pressure of input versus internal pressure, the pressure indication goes down as the temperature goes up!

My solution was simple - remove the rubber plug, drain the silicon liquid, drill a small hole in the rubber plug, and then reinstall it so it can vent to atmosphere. Although the liquid can dampen needle jitter, I find that jitter has not occurred because I connected it with a small diameter 1/8" feed line from the carburetor which dampens any oscillations.