The dirt was a black deposit of some sort in 1 side of the carb. My initial thought was the ethanol in the gas was deteriorating the rubber portions of my fuel line so I replaced the fuel filter and the rubber fuel lines but still no good. It has a new fuel tank but I guess it could be dirt plugging the pick up but why does it run fine for a few minutes and then act up? This car has not run right from day 1. When I first got it, it had a slight cruise speed (40-45 mph)miss that I finally solved by disconnecting the vacuum advance. First time I drove the car to a show the brand new fuel pump crapped the bed. Next it was the voltage regulator next the alternator next the power steering pump(twice). I've replaced the coil, ballast resistor, ECU-still misses. It's been totally unreliable!