Someone explain IPR to me

[Stroked7.3]

I know the IPR has a screen on it that is known for cracking and what not. But is it enough to cause a no hot start? Im having hot start issues sporatically. Sometimes its fine for a week then it wont start for a week. We've already replaced the dummy plugs and standpipes. Icp is pulling 500psi at idle. So my mechanic and I are thinking the IPR is acting up. Any suggestions?

[diablos30]

have you installed the upgraded stc fitting? if not then that is your likely culprit.

[npccpartsman]

The IPR controls the HPO pressure as commanded by the PCM. If the screen on the IPR valve is trashed up or compromised then the valve can fail to operate properly or close. If it doesn't close all your HPO gets dumped to sump and you have zero pressure. Pull the valve and check the screen. If it's covered in trash you might get away with cleaning it. If it's got a hole in it then replace the valve. If this doesn't fix your problem then you have an HPO leak, STC fitting being the most common problem.

[sinner6.0L]

Think of the IPR as a controlled leak. The HPOP builds a certain amount of pressure per RPM and the IPR relieves the excess based on what duty cycle the PCM commands.

[Stroked7.3]

so what would I need tool wise as well as how would I go about removing ipr to check the screen?

[sinner6.0L]

a good tool to have for the IPR is the special socket that removes it. here is a link

Amazon

Amazon

If you have this, and a 3/8s universal + an 6-8" extension you can get the IPR out by removing the FICM and rear FICM bracket. fairly easy to get in and out that way, it's the only way I do it anymore.