Holding Fuel Pressure after Shutdown

[nick_968]

I have a hot start issue that I have narrowed down to fuel vapour lock. After fitting a check valve on the supply line this has improved by about 30% but the fuel pressure still drops after shutdown, just a little slower than before. Within 2 minutes it is down from 45psi to 20psi. The engine is turbocharged and gets quite hot and I have eliminated all other possible causes. I have a fuel lab adjustable fuel pressure regulator and some reading on their site confirms that it is not expected to hold pressure due to its design and that a check valve will slow things down but this is not enough. The only other thing I can think of is that the regulator itself is faulty and the diaphram is gone but it does not appear to leak anything into the vacuum line which in theory it should if the vacuum line is gone. There is also a raw fuel smell around the regulator area but I have replaced and checked all the lines.

Can anyone recommend an adjustable fuel pressure regulator that will by design hold pressure on both the flow and returns after shutdown to the same levels as you would expect from a factory non adjustable regulator?