hpop low pressure
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Freshman User
Joined: Oct 2006
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From: On a farm
hpop low pressure
I have a 99' f350 with 180,000 on rebuilt engine I just replaced the hpop, icp, and ipr because the truck was stalling I thought I got it fixed but it just started stalling again. I have a auto enginuity scan tool when it stalls the pressure goes below 350 then stalls out. It does not do it all the time only after the engine is really warm, it takes about 1/2 hour of driving then it will start to stall. If I wait about 3-4 minutes it will start back up.
thanks for help
thanks for help
Senior User
Joined: Aug 2004
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From: Racine Wi
Have you monitored the ICP duty cycle when it is dying. If your duty cycle is dropping at the same time the pressure is dropping, then something is telling it to shut down. If the duty cycle is rising and pressure dropping (what I suspect), then you are probably running out of oil in the resivoir which could be a symptom of a poor performing LPOP. Just something to check. The engine needs about 500 PSI to idle
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Freshman User
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From: On a farm
I forgot to mention that I replaced the lpop at the same time as the hpop. When i check the resivoir after it dies it is 3/4 of an inch away from full, i believe that is the correct level.
thanks
thanks
Fleet Owner
Joined: Jun 2004
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From: Rio Rico, AZ.
Sometimes the oil pickup tube in the crankcase for the LPOP gets a crack in it.
The way to confirm such a problem is to overfill the crankcase and jack the rear end way up in the air or park it on a very steep hill, nose down so the oil will cover the LPOP intake flange. If there is a crack, the stalling, low HPOP, etc will disappear until the truck is leveled out and correct oil level is restored.
The way to confirm such a problem is to overfill the crankcase and jack the rear end way up in the air or park it on a very steep hill, nose down so the oil will cover the LPOP intake flange. If there is a crack, the stalling, low HPOP, etc will disappear until the truck is leveled out and correct oil level is restored.
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Post Fiend
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Good point Dan but I'm thinking his HPOP reservoir would not be so full if he had a LPOP issue. The next time it does it, immediately unplug the ICP and see if it will start. You may have a connection problem at the ICP or IPR. Also, check the nut on the back of the IPR and make sure it is tight. Good luck.
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Freshman User
Joined: Oct 2006
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From: On a farm
If there is a crack in the pickup tube then the hpop resivior should be empty after the truck dies. mine is full. Am I correct or is there a sensor that will shut the tuck down if there is no oil pressure. I cannot remember what the low pressure oil gauge reads before the truck dies.
thanks
thanks
Fleet Owner
Joined: Jun 2004
Posts: 25,090
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From: Rio Rico, AZ.
I thought the HPOP reservoir might get all filled up with oil foam due to the airation and that's why I suggested the cracked pickup tube. Shut the engine off, the oil settles out and there is the big bubble at the top of the reservoir.
Or...............
There's a HUGE bubble that is compressed down in the rails and when you shut it down the air expands back out and forces the oil into the easiest place and that just happens to be the HPOP reservoir???
Casting about right now.
I'll be the first to admit I was wrong, just trying to find an explanation for the tapering off of the HPOP pressure.
Or...............
There's a HUGE bubble that is compressed down in the rails and when you shut it down the air expands back out and forces the oil into the easiest place and that just happens to be the HPOP reservoir???
Casting about right now.
I'll be the first to admit I was wrong, just trying to find an explanation for the tapering off of the HPOP pressure.
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Freshman User
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From: On a farm
I haven't had a chance to try it yet. I tried to start the truck but it is below zero and I ran the batteries dead. I forgot to mention that ever since I repalced the hpop and lpop it cranks longer to get started. Also I have a six speed and when the truck stalls then dies the high oil pressure goes below 200 and will not go high no matter the rpms as i down shift. It will only die after I drive it below 50mph or 1000 rpm for a half mile or so.
Fleet Owner
Joined: Jun 2004
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From: Rio Rico, AZ.
Originally Posted by powerfarmer
I haven't had a chance to try it yet. I tried to start the truck but it is below zero and I ran the batteries dead. I forgot to mention that ever since I repalced the hpop and lpop it cranks longer to get started. Also I have a six speed and when the truck stalls then dies the high oil pressure goes below 200 and will not go high no matter the rpms as i down shift. It will only die after I drive it below 50mph or 1000 rpm for a half mile or so.
I still think air.
It must be compressed before enough pressure is built up to fire the injectors and that takes cranking time to do so.