I disconnected the fuel line at the engine driven pump and screwed on a fitting which I had attached to some ½” clear vinyl tubing. I poured about a gallon of fuel into the left tank, then turned on the fuel pump. Pump runs, but no fuel coming out of the line. So, I wondered if I needed more fuel. Went to the FBO and got another 2.5 gallons—poured this into the left tank--still nothing. I raised the tail so that the plane was almost level and I could see fuel in the tank—still no fuel flow. Then, I started fiddling with the fuel valve—rotated it from L to R to off and all around. I checked the handle and I had not tightened it up completely, so I fixed that issue. I turned on the pump and now the fuel flows just fine. I pumped about a gallon into a jug which I poured into the right tank. With the pump on, I rotated the fuel valve through all of the various positions. Fuel flows from the left tank, stops when the valve is in the off position, then flows again from the right tank. The fitting that connects the fuel line at the right tank had a slight leak which I cured with about a quarter turn of the wrench—no other leaks noted. I emptied the catch jug back into the right tank. I turned the pump on and ran it for 20 seconds. The output was a little over a quart of fuel. That calculates out to about a 45 gal/hr flow—plenty enough for a 180 hp injected engine. I did a repeat test on the left side—same result. I connected the fuel line back to the engine driven pump. I’m calling the fuel system check out complete. Done, done and done!