Does it crank too much both cold and hot? Run OK after it starts? Crank speed OK?
When you go to start the car after it hasn't run for a couple of hours, turn the key just to the "On" position. You should hear the fuel pump run then stop. Now turn the key to start.
Does the engine still turn over several times before starting?
When you leap in your car to start it and turn the key all the way to start, your battery is trying to run two pretty hefty electric motors; the starter and the fuel pump (plus whatever you left on when you shut down last- blower, radio, seats, etc.).
See what happens when you ask it to run just one motor at a time.
The weaker the battery is the more you need to baby it and not ask for too much at the same time.
To test the FPR you need to tee into the system. Depending on the model you're looking for 2.5 or 3.0 bar gauge. (Bentley section 6.5) It'd be interesting to see how fast the pressure bleeds off after the engine is shut off and the pump shuts down. It should stay up for a really long time.