IPR
 

Is there a way to check a ipr without having to buy external guages.While cranking the truck doesn;t have enough oil psi to start according to my scanner.Customers truck is a 01 f350 180,000 miles.Checked oil res. and it was very low,refilled but still didn't have enough psi.Let it sit overnight and the resivour was down again.
ps truck was towed in.

Look at the ICP pressures and duty cycles... I would bet the IPR is plugged. You can remove it and clean it pretty easy...

https://www.dieselbombers.com/ford-d...l-rebuild.html

Cleaned ipr,didn't really see where it was stuck.Reassemble filled resivour,took a little cranking but it came to life.Letting it sit to check drainback at this time.MANY thanks!

You will never see where, it takes the smallest piece of crap to stop it dead in its tracks...