Hey need help with a stubborn 6.0L. It has new 90hp injectors, egr delete, new ipr valve, one piece STC, stand tubes, snubber valves, and dumby plug. I had it running poorly for 3 days and forgot to tighten the return line on the upper fuel <NOBR style="FONT-FAMILY: inherit; COLOR: darkblue; FONT-WEIGHT: bold" id=itxt_nobr_1_0>filter</NOBR> housing. So I drove 40 miles home and turned it off and now it will not start again. I have pressre tested the HPO system and can only hear air bubbles from the pick up in the oil pan with the ipr closed. I have a HPOP coming Monday but was just looking for conformation that this bubbling is the sign of the weak HPOP. Thanks

 

I just posted a story about my expierience with this and tried to make it short so I left out some stuff but yea after a couple hours of the air pressure test with both valve covers off and pump cover off, all I could hear, barely, was air at the front of my engine at the oil cooler or oil filter base. So I guess if you run the test long enough, air goes through the pump, down the passage way to the oil cooler and can keep on going. I don't know if only bad pumps let air go through them, I never air tested a new pump.

 

Did you replace your HPOP. Thanks for the help so far but has anyone tested a good HPOP and had the bubbling in the bottom of the motor??

 

I read your lengthy post. Great stuff . I did see where it was "normal" for air escape from around the pump shaft on even new pumps, and I would think that air would be able to bypass eventually with enough time and pressure on an old system.

Wenuck72---he did replace his pump.

 

I changed the HPOP and the Ford lives again.