Been searching around for a while but still can seem to find an answer for what’s going on. About a week ago my 2007 f250 would crank but wouldn’t start. Started getting into the usual suspects such as replacing icp sensor and pigtail as well as the ipr. Still wouldn’t start. Monitoring on the scanner the ipr is at around 14% KOEO and jumps to 84% while cranking. Icp reads 0 psi at KOEO but only gets up to 250ish psi while cranking. Good low pressure oil, HPOP replaced around 25,000 miles ago. Did an air test in the icp and ipr with both valve covers off and couldn’t hear anything. The stand pipe and dummy plugs were replaced on both sides recently and there’s no copper in the oil indicating the HPOP has gone bad again. I’ve been searching for the past week looking for answers but it’s always something related to the high pressure oil system but from everything I can tell mine seems okay other than the fact that it just won’t build enough pressure to fire the injectors. Any input would be appreciated thanks

 

Why was a new HPOP installed? The '05 and up HPOPs do not go bad often, unless there is a starvation of oil or debris is run through them.

Where was the IPR valve purchased from?

You say you have good "base oil pressure"/ How do you know this? The Dash light is not a pressure gauge, it is only a switch that moves at 5-7 psi.

From what you have posted, you have insufficient pressure in the high pressure system. That MUST be caused by one or several of the below )assuming accurate ICP readings):
Leak
Bad/weak HPOP
Mechanically failed IPR
Electrically (or electronically) failed IPR
Insufficient low pressure oil supply

FYI - The way you can verify that the ICP is not involved in a no-start is:

• unplug the ICP sensor and see if the condition changes
• get the sensor output volts at Key-On, Engine-Off
• get the sensor output volts when cranking
• compare the PCM value for ICP pressure with the sensor voltage output

So many people just start replacing parts and this can actually impair the troubleshooting process.

Post a picture of the top of your engine please.