FWIW, when you de-pressure a fuel system, there's not much 'expansion room' to force the pressurized fuel out. In other words, you would not expect a large squirt of fuel out the schrader unless there was a lot of expansion in the fuel lines that was being released.
I had a trailer hitch in my 85, and could get it to go away by plugging the EGR vacuum line. Replacing the EGR valve was not the solution. I had bad plug wires causing misfire under mid speed - 40-50 mph operation. New plug wires cured the problem.
Try doing a fuel pump 'delivery' test. Borrow or buy a gauge with a diverter valve you can open to collect fuel[and release the pressure]. Run the test by starting the engine, so the fuel pump will continue to run, and diverting fuel into a suitable container for X number of seconds. If you don't get ~Y amount of fuel in X seconds, your pump is not delivering enough fuel. I don't have X or Y at my fingertips, but if you can get a cup in 15 seconds, you have more than enough. 60 mph at 15 mpg would mean 1 gallon every 15 minutes, so you can see about a cup every minute [1gal=4qt=8pt=16cups] is an approximation.
tom