hpop issue
hpop issue
My 2000 7.3 quit on me today, checked fuel pressure, good, replaced cps, still wouldn't start, pulled hpop line at head and have no pressure, zero. question, do hpop's just die like this or could something else be causing it? have good engine oil pressure too...
Have you pulled the plug on the top of the hpop reservoir to very you do indeed have oil present? Not saying it's not the hpop, but read this first.
Here is a partial quote taken from another similar thread:
Originally posted by Dave (Golfer) on PSN 01-20-2010 Thanks Dave
its nevvvvver the oil pump...seriously.
I see sooooooooooooooo many guys (dealerships included) that see "no ICP" or some ICP codes in a scantool...and toss HPOP's on truck after truck...when it is either an IPR or an injector (poppet valve) issue.
Hook up the scantool, and monitor ICP PSI and ICP Duty Cycle %. while cranking...you'll see IPR% (duty cycle) climb & climb 15% key on..20, 30, 40, 55%, higher..the increase in IPR% means that the PCM is requesting ICP pressure to increase...
so ALSO watch ICP(psi) and if it comes up to only 180-250psi or so and stays there...then it's the IPR hung open (bypassing oil back to the oil pan through the front cover) such that only minimal psi can be made.
If the ICP is VERY low...like under 60psi...then it could be injector (poppets) pissing oil (under the VC's)..which is typical for injector with more than 180-200k miles.
if ICP climbs above 550-600..then it will probably climb much higher (15-1800+) and it is most likely going to be an electrical issue.
Here is a partial quote taken from another similar thread:
Originally posted by Dave (Golfer) on PSN 01-20-2010 Thanks Dave
its nevvvvver the oil pump...seriously.
I see sooooooooooooooo many guys (dealerships included) that see "no ICP" or some ICP codes in a scantool...and toss HPOP's on truck after truck...when it is either an IPR or an injector (poppet valve) issue.
Hook up the scantool, and monitor ICP PSI and ICP Duty Cycle %. while cranking...you'll see IPR% (duty cycle) climb & climb 15% key on..20, 30, 40, 55%, higher..the increase in IPR% means that the PCM is requesting ICP pressure to increase...
so ALSO watch ICP(psi) and if it comes up to only 180-250psi or so and stays there...then it's the IPR hung open (bypassing oil back to the oil pan through the front cover) such that only minimal psi can be made.
If the ICP is VERY low...like under 60psi...then it could be injector (poppets) pissing oil (under the VC's)..which is typical for injector with more than 180-200k miles.
if ICP climbs above 550-600..then it will probably climb much higher (15-1800+) and it is most likely going to be an electrical issue.
If you pulled the HPOP linewth the engine off, you won't have pressure there. If you pulled it off with the engine running, you must be crazy!
Have you pulled the connector off the ICP sensor and looked for oil? That is more likely a cause than the HPOP.
Have you pulled the connector off the ICP sensor and looked for oil? That is more likely a cause than the HPOP.
Going along with what Ken said ^^^. Have you tried starting it with the ICP sensor unplugged? You could have a faulty sensor. If so, it should start with a default setting due to the open circuit.
Pull the cover to the HPOP drive bolt. See if the bolt for some reason has come loose? The HPOP drive gear is driven by the cam gear. If for some reason that bolt were to come loose, it would make the HPOP not turn.
The only other thing is if the IPR is stuck full open. That would keep the oil pressure from building too. This is more likely than the bolt being loose.

The only other thing is if the IPR is stuck full open. That would keep the oil pressure from building too. This is more likely than the bolt being loose.

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Bolt wasn't loose and valve checked good and the ipr solenoid checked good. so after all this the only thing left is the pump, got one on order, will know the outcome tomorrow. Thanks again for all of your input.
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