I'm trying to figure out if my HPOP is weak. My truck starts good when its cold and runs good as long as you don't shut it off. Once the engine is warm the truck won't start. I put a pressure gauge on the cylinder head today and got these readings. When first started and at idle the pressure was at 1200psi. That pressure dropped to about 700psi at a idle warm. When trying to start warm the pressure was at only 200-250psi. Are these numbers right? The warm pressures seam low to me and make me wonder if the HPOP is gone.

 

yes those pressure are low but not cause you HPOP is shot. Its much easier and cheaper than that. More than likely your IPR o-rings are bad. For $40 you can get a new set and replace them in under an hour. also could be injector o-ring or injector issue but 95% its the IPR o-rings

 

i am beaten again

 

IPR O-Ring Kit (for when IPR valve replacement is not required)
(Ford) F6TZ-9C977-AN (F6TZ-9C977-AA?)
(International) 1825806C92 (1825806C91?)

procedure
http://cw-diesel.com/LuxSite/IPRInfo.htm

 

where is the ipr?

 

It threads into the back of the HPOP down low to the driverside

way down deep!


another view. its got the hex on the end

 

look....here,,,,,

 

Some info.
http://cw-diesel.com/LuxSite/IPRInfo.htm

Bill

 

Thanks for the replies everyone. I'll have to give that a try.

 

Finally got some time to work on the truck this week. I pulled the IPR and sure enough the two small o-rings on the end of the IPR were dried out and there were chunks of them missing. I cleaned it up like the link that was posted showed to and put it back together. Truck starts fine now. Thanks for all the help. The best part is with my company's discount at International the o-ring kit came to $20 bucks.

Thanks,
David.

 

Great to hear! we love the cheap fixes!

 

Cool!
I can only imagine how many pumps have been changed, all do to a IPR o-ring.

Bill

 

I too changed my HPOP right after purchasing my truck. Same symtoms, hard start after it was warm. I knew very very little about our powerstroke engines so I carried it to the stealership. They told me the pump was bad, cavitating, causing the oil to foam, which resulted in the hard warm starts. I did not have them change it, did it myself, which did cure the problem. But, the pump came with a new IPR and seals.

Now I am thinking ........... u know

Them Stealership *****ers

 

how difficult is it to change out the hpop