I know that Sam tried to install a fuel line check valve w/o success because of the non-reserc fuel system used on the 03 XK's.

Has anyone successfully installed one of these on a earlier model? I am about to install one on my car but would fill better if I knew it was going to fix my long cranking when cold problem.

Thanks!

 

The 4.0 cars don't have a returnless fuel system, rather, it is a continuous loop from the tank, a pressure regulator (in the engine area I believe), and a return line for unused fuel back to the tank. If you have a pressure issue or a pressure bleed off when the car is not running, it is likely the pressure regulator, and I believe you are asking for problems putting in a check valve. Classic symptoms of a marginally bad pressure regulator (bleed off) is when the car is hot then is shut off for 10-15 mins, then hard starting (long crank times). Cold starts usually are ok with a marginally bad regulator, however, a pressure regulator that is failing surely could cause long crank times when cold too. Get a pressure gauge, they are cheap. A regulator is probably easier to replace than fitting a check valve.