Fuel Pressure dropping

Thanks guys (and especially Crossrambler in NV), you helped me realize that my new liquid filled fuel pressure gage was giving false low readings! In hindsight, it's easier to see how the elevating temperature under hood makes that liquid expand and builds up pressure inside the gage, screwing up the action of the Bourdon Tube in the gage. If you Google this topic there is A LOT out there, now I'm better educated. I never thought to mention the new liquid filled gage since I had a gage there over the last 5 years (a "dry" cheapie Mr. Gasket that finally failed) and the initial new reading was spot on, so I trusted the new gage.

My fix was to drill a tiny hole (.039" in my case) in the top of the gage so the pressure inside stays equalized (others apparently have done the same). There's even one gage out there with a bleeder valve on it just to address this common problem. Once the engine bay is warmed up I can pinch my finger over that hole and watch the gage loose half a pound of pressure in about 1 minute. When I release my finger it immediately returns to 6 PSI.

So now I can further assume that my very occasional lean stumble is not due to low pressure/half empty fuel bowl (unless I miss diagnose that too and it's not a lean stumble). I'll try a bigger squirter for that...last jump up in squirter size made thing seem better.

Dave