You don't have any "Vapor" lines. You have one fuel line that runs from the pump to the fuel rail on your engine, then one line that returns unused fuel from your engine back to the tank.
If the high-pressure line had a crack in it, you'd see fuel spraying out of it, and this would start a fire almost immediately. And you would have more than just a "hard-start" problem.
If your return line has a crack in it, fuel would leak out more slowly, but it would still be dangerous. However, it wouldn't cause you any driveability problems.
You should check your Fuel Pressure Regulator.
First, pull the vacuum line that runs to the FPR and check for the presence of fuel. (Touch, smell) If there's any, then replace it.
Next, hook up a fuel pressure gauge. With your key on/engine off, you should read 41-47 psi. Watch the fuel pressure for at least 15-minutes.
If the pressure drops more than a few psi, then there's a leak in either the FPR, one/more injectors, or the check valve in the pump or filter.
If there's a leak, then first pinch off the feed line from the tank and recheck pressure. If it stops leaking, then your check valve is leaking. (Stuck open)
If pressure is still leaking, then pinch off the return line from the engine back to the tank. If it stops leaking, then your FPR is bad. If it still leaks, then it's one/more of your injectors is bad.
Thursday, March 18th, 2010 AT 9:36 PM