Ok I am New here so please try to go easy on me. I am working on a buddy's 2002 ford F-250 7.3l Powerstroke. Original problem ( and still is ) an intermitent no start problem. The truck would not start after sitting over the weekend. Its a daily driven work truck but the mantaince has been kept up with. 250,000 miles. Did a scan found no codes. Reset the computer still no start. Run buzz test (all came out loud and clear). Truck started right up , and continued to start over the next 2 days. Then no start again. Went back over scaned again no codes. Checked the flex hoses from frame found one leaking so I replaced all three. Truck started and ran good 4 more days then no start. Went back scaned again found code p 1212 ( low ICP durring cranking) . Checked oil in hpop (full) Just for grins pulled out fuel pressure regulator found small rubber "thing" in orfice cleand and still no start. He had a diablo preditor but it was not running on this truck . Hooked it up used its diag. feature and go p1212 code again and still no start. Used It to up the tunning to the 110hp seting the truck started right up. Reset tune to origianl back up and truck still started fine. I am still worried that it is not fixed. Thinking of pulling the ICPR out and checking it in the morning. o yea i forgot to mention so far every time the truck does start after sitting all night there seem to be no running problems . Does it sound like I am on the right track ??? Hate to say its fixed and it leave him stranded away from home, I am a mechanic but have very little expereince with automotive diesels. Most of mine has been with equipent and if I havent Physicaly seen some thing to fix I dont Feel like its fixed . Please help. Sorry its so long but as a mechanic I know the more I give you the easier it is to answer!!! Thanks in advance for your help.

 

Sounds like a leak down issue on the HPO side. You need to watch ICP and duty cycle the next time it does its no start issue.

But it has every indication of a leak down problem.

 

Thanks that will be the next thing to check . This morning it started right up and ran fine but I will get back to you if it does it again. What kind of value would be normal for ICP duty cycle and voltage. I forgot to look at those when it would not start.Thinking that next time it happens I am going to Data Log it so I can go back and look at things after the fact.
If level in res for HPO is full Where else do they leak ? (probably under the valve covers where u never notice FUN)

 

There is no normal... ICP duty cycle changes as you drive. At idle normal would be anywhere from 8-15% and 400-800psi...

At WOT it can be from 40-70% at 2500-3500psi...

 

ok so its back with no start after 4 days of sitting and then 3 days of running on 4th day it would not start. Found some crud in the resivor and found that the IPR valve has the correct duty cycle and pressure . Pulled it out anyway and found that the small pin in side that controls the orfice has a score in it. Going to replace that and clean resivor. Put gauge on the injectors and found that with the engine off and a hyd pump attched that they would slowly lose pressure ( or 3-4 seconds) dont know if that is normal or not but does not sound good does it??

 

Did you ever solve this problem? I know it has been a year but would love an update. After 2 days of diagnostics and research I found that after "tapping" on my fuel pressure regulator, the engine fired right up. took apart regulator to clean and found same piece of rubber/debris on orifice. I ordered a rebuild from dieselorings.com and will do that later. Time will tell but it seems like a very clear fix to me.

 

Yes removed hpop res and replaced gaskets the lower gasket had a screen in it that was dirty. And replaced IPR valve and seal. He has been driving it ever since and no problems. He drives about 15,000 miles a year and I see him ever few weeks every time I ask he says still running great.

 

Thanks for the update!

 

Just an update... truck is still running great with no problems since . Thanks for the help guys.