Rail pressure monitoring with edge insight

[mweiman]

For those running an edge insight, how good is it as a rail pressure guage? Can you get a fairly accurate reading while cranking the engine or does the monitor drop out? I am thinking of getting one to put in the 03 I recently bought and keep it set up that it could be removed easily to use to troubleshoot other trucks. If not what is a good rail pressure guage or scan tool to buy that would read rail pressure?
Thanks,
Matt