Ford 7.3 injection pressue leak

flattop1

flattop1

Dawg 89
Anyone have issue with no high pressure injection pressure when hot vs cold . Starts right up cold , hot need too crank 10 seconds or more too build pressue . Replaced all the orings , and sensors and injectors . Air tested high pressure side .
Any ideas ?
Thanks Tony
 
Dealing with a similar issue.
Injection pressure regulator. or High pressure oil pump.
Some threads I read suggested oil too thin when hot.
Also, when Ford first started using the 7.3, there were issues with oil foaming. Modern diesel oils now have antifoam capabilities not in regular gas engine oils.
Mine is in a van, so really difficult to work on.
 
The oil thing i suggested to the owner son . He pu pued it , still a possibility as hes been working on it for a while .
Against my advice he didnt take in for diagnoses . So now hes got all new preformance injectors , new chip , sensors everything but the hpop.
New forscan program with wireless pressure gauges the works .
Runs full Pressure above spec . But bleeds off when you turn it off and go in to the store . Hes ran with the pressure regulator plugged and no change or leaks .
I suppose it all lead to the hpop . Thing is this wasnt the Original problem , which is normal .
 
Does the hpop reservior stay full, or drain off?
I do not believe it has a pressure accumulator, so pressure will naturally bleed off.
Did he try with the stock tune?
I have an old superchips tuner, when turned up to performance modes, takes longer to start. Haven't had my analog gauge on it yet to see where the pressures are. Engine oil pressure is read directly from reservior. Not sure if ecm must see pressure before it allows start.
 
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Not sure , I'll relay the info .
Something must see pressure it wont start till it builds pressure .
 
I had a buddy who used to brag about the engine telling him when it was time to change the oil. Hot crank times ..... He and that F250 are long gone. He is missed.....
 
if this was me I would check the icp senseor it needs to see pressure from the high pressure oil pump. ore it will crank till it sees
700-900 lbs pressure then it tells the idm to open injectors. if apr valve has a slight leak it will also cause problem when starting.

do your self a favor check the screen in oil tower for dirt you can remove and clean with brake clean .
most inporten thing a 7,3 liter needs in clean oil rotella 15/40 and a good filter.

PS flat top 10 seconds is not a lot or time.for 7.3 liter
 
flattop send me a pm with your # and i can try to walk you through it.
35 years and retired on these diesels when they run you can't beat them.
 
Yea i could be wrong about the ten seconds , he says its a long time .
New icp .
APR valve ?
Screen idea sounds good its got some miles on it .
 
95 shaw said:
Does the hpop reservior stay full, or drain off?
I do not believe it has a pressure accumulator, so pressure will naturally bleed off.
Did he try with the stock tune?
I have an old superchips tuner, when turned up to performance modes, takes longer to start. Haven't had my analog gauge on it yet to see where the pressures are. Engine oil pressure is read directly from reservior. Not sure if ecm must see pressure before it allows start.
Click to expand...
No hpop stays full .
Same in all tune modes .
The idm controls the injectors not the pcm .
 
If the reservoir has oil an inch from the top & the rest of the high pressure system test good, It has to be the High pressure oil pump. The only other thing is what does the ICP read when it acts up?? Should be close to 0.18. Sometimes I swap ICP sensors with one in my box just to see what happens. Could be a cut o-ring on the IPR when he put it in.
 
I have seen a lot of PCMs damaged by chips. They get loose & all kinda stuff. Man, I just wanna start workin on it right now. LOL
 
Roger .
A good icp reading is 0.18 ?
He just changed all the o rings .
I had a super chip tuner in it he swaped for a custom tune for single shot injectors , just recently .
Loose would be intermittent would it not ?
 
Loose would be intermittent would it not ?
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Sometimes they wont start when the chip gets loose. We tape over them to keep it from happening. Because that will damage the PCM. 18 is a good ICP. 0.18v key on eng off. There are o-rings on the IPR that go bad too. Up in the pump. That would be the first thing I checked if I was workin on this truck right now. Take the elec. part off of the IPR and take the mechanical part out and check the o-rings for cuts from hot oil. If you dont see bad o-rings, put a known good IPR in & retest it.
I misread. I thought it had a new IPR installed.
 
No you read right it does , all new sensors , idm the works .
Fuel rail o rings anything leak related
Everything but the hpop .
 
I just got the gas tank out of my town car . On jack stands so I'm tied up right now . ;) . It probably be easier cause I can't find my own tools so finding yours should be easier .
I put that off for a year .
 
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