Desired & actual FRP ?
Injector leak off ?
Pump proof test ?
Does it have pressure relief at the rail like the Transit does ?
It will be a SCV not IMV on a Denso system.
No doubt if it's that it will want a re-learn.
system tries to bring rail pressure back in line
How do you know that if you think you need to scope the SCV current & volts ? live data ?
What scan tool are you using ?PS
post your captures so we can see what you've got ?