So I've replaced my standpipes and dummy plugs. I also replaced the STC fitting. I'm still having a problem with hot no start; long crank. It does eventually start but I get some very long cranks when hot.

My readings for ICP, IPR and FMP are all good when cranking hot but no start. I am trying to air test it but I am unclear on how to close the IPR valve? Does it need to be closed? Once I do this what exactly am I to listen for? I do hear air through the filler tube but I heard this without doing anything to the IPR valve. Thank you.

Also interested in hearing opinions on the "Traditional Method" paragraph of this link 6.0L High Pressure Oil System IPR Air Test Tool as well as the tool they are selling itself.

 

4 ways to close IPR

IMO the air test is not worth doing unless you hard pipe the air supply (ie the rubber tipped air tubing applied to the ICP hole is not reliable).

If you can't close the IPR valve for whatever reason, then it definitely is not worth doing.

4 ways to close the IPR:
1. Software like IDS to comand it closed (maybe AutoEnginuity will do it)
2. Buy an IPR connector and wire it up to apply switched power to close it: Red wire switched power Pin A: apply B+; Yellow/red switched ground Pin B: Apply B-
3. You can close it by having the key in the RUN position, and jumping pin #2 of C1381c (the middle of the three PCM connectors between the driver side battery and the inner driver side fender well which requires the battery cover removed to access) which will be a yellow wire with red stripe. This is the ground side wire to the IPR.
4. Tool to close the IPR: Automotive Tool Web-site - DenLors Tools; OTC 6764 Ford Diesel 6.0L IPR Controller / Tester

OTC 6764 Ford Diesel 6.0L IPR Controller / Tester | Multimeters, Amp Clamps, Test Leads tml


Don't hold the IPR valve closed for more than 2 minutes. I have been told it is OK to do it longer, but I don't want to put someone elses IPR valve at risk.


Allow enough time for the air pressure to push the oil out of the rails, that can take a minute or more.

 

Hhc diesel (creator, and robbinthahood) are who you should contact. Get the IPR test fitting and test. This way it's a strictly mechanical test. Rusty is on it when he said it could take a while for the nipple cup to show itself (which is prob the issue). How many times have the oil rails been off??

 

Oil rails have never been off as far I know.

 

Im dealing with the same issue. Pretty sure its a dummy plug but im apdating both and standpipes as well. If it is in your nipple cups or injector, maybe this will help if you havent seen it already. Good luck!

https://www.ford-trucks.com/forums/1...ole-story.html

 

While a mechanical test is always best (using an HHC Diesel IPR test plug of course an ICP port test can give an average Joe a good place to start.

IMHO:
I think everyone is way to paranoid about burning out their IPR valves with 12volt power. It is a full duty solenoid built way better than those used to control everything from sprinkler systems to factory machinery(which all use constant 12-16volt power). It can handle way more than 2 minutes of 12 volt power. It's the internal piston and ports on IPRs that clog up an fail generally. I have accidentally left my IPR connected to the battery for an hour and it is still running fine.