I'm thinking maybe my return fuel line is plugged. Can someone tell me which one is the return line at the rail, is it the smaller diameter line I'd like the blow compressed air and see if it goes through. The car will start first thing in the morning and it seems like it's running really rich black smoke coming out the tailpipes. After that it won't start up until I pull the fuse for the fuel pump and then a few minutes later it will start but then die out of course without the fuse in.