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+--- Thread: Odd fuel pressure issue (/showthread.php?tid=7802)
Odd fuel pressure issue - Lweuve9 - 10-24-2021
So I have a 2014 demandated isx15.
Back story
I replaced the pressure relief valve on the rail a couple months ago because the psi was all over the place with surging at idle. Replaced and solved the problem
Yesterday, I was coming down the side of Monarch Mt and blew the (Fuel pump gear pump outlet) line. I replaced with a 35psi hose from Napa to get me down the road and when I started it, it was blowing white smoke smelling like unburnt fuel. I made it 20 mi and blew it again.
I replaced it with another hose, cause I was smart enough to get enough to make 2, and made it back to Napa and had them make me a 3500psi hydraulic hose to get me back home.
The hose is holding up, but here is the issue...
At idle, I'm commanding roughly 9400psi and it measures 36000.
Running down the road, having the cruise set, it will either not come above 14000, or sit at 36000.
To add to this, when on the pedal, the measured pressure will match the command pressure, 90% of the time, as long as the engine has a load on it.
And when you give it the beans and command 36k, it'll give it 36k, unless it's on its 14k kick as said above.
I did change filters to see if that was the issue, and it didn't make a difference.
Obviously getting high rail pressure code out of the whole ordeal as to be expected.
And the first diagram on this page, or the attachment below, I blew (#5), but on my engine it is plugged in to the (#8) spot on the side of the filter housing
{link removed by Rawze}
Thank you in advance for any help.
RE: Odd fuel pressure issue - tree98 - 10-24-2021
Run the leakdown test on it with insite and fix the leaks and start from there.
RE: Odd fuel pressure issue - Lweuve9 - 10-24-2021
(10-24-2021 )tree98 Wrote: Run the leakdown test on it with insite and fix the leaks and start from there.
Any ideas on why the first hose blew?
RE: Odd fuel pressure issue - Rawze - 10-24-2021
First and foremost, you need to start by assuming that your "delete" programming is bad. This is a 90+% likely chance across the trucking industry. It does not matter how you "feel" it runs.
NEXT: for all you know, the programming could be demanding those wacky numbers in the background and your not seeing, due to horrible, hack-n-slash delete programming. It is quite often the clowns who made that program, they ack with the fuelpressures in very bad ways and it over-works the fuel pump and all sorts of other things, leading to problems.
Get yourself a cheap laptop, and an inline-6 adapter off flea-bay for a few hundred bucks and pull the programming out of it .. e-mail it to me and I will review it and tell you if it is any good or not.. or if it is causing problems.
Here is some light reading on this subject...
ref: http://rawze.com/forums/showthread.php?tid=1558&pid=13255#pid13255
ALSO: How old is the guts inside the fuel pump itself?.. if it has more than 8,000 hours or 400k miles on that fuel pump.. its time to pull it apart and replace all its guts to prevent total engine destruction without any warning.
ALSO: You need to get the proper OEM hoses back on that thing.. DON'T SCREW AROUND with the fuel lines like that.. It is severely dangerous and can lead to some real problems!.
Priority #1... fix the fuel lines that were buggered-up with OEM hoese.
Priority #2... Get the program reviewed in that thing so that you know your not fighting the ghosts of a bead delete program that is he#$ll bend on destroying your engine.
NET: is WHAT was done to the hardware... many de-mandate shops do horrible things to these engines when doing those types of mods ... all in the name of setting your equipment up to destroy itself while they brag about how good they are at what they do.
RE: Odd fuel pressure issue - Rawze - 10-24-2021
(10-24-2021 )Lweuve9 Wrote: ...
And the first diagram on this page, or the attachment below, I blew (#5), but on my engine it is plugged in to the (#8) spot on the side of the filter housing
{link removed}
Thank you in advance for any help.
YOU ALSO NEED TO sign up on quickserv.com.. its totally free, and you will have the PROPER diagrams and everything else instead of some out-of-date stuff that you posted the links to.
RE: Odd fuel pressure issue - Mr Hagg - 10-25-2021
90% of the time when I have higher fuel pressure like that its the fuel pressure regulator in the back of fuel pump. Most of the time you will here like a serging sound where relief valve is doing its job and relieving fuel pressure from high pressure rail. THus causing alot of return fuel maybe why you blew the rubber line. Id start there first. ALso note the plug for it is not at the regulator but about 6 inches away on the block...
RE: Odd fuel pressure issue - Lweuve9 - 10-25-2021
The truck has been on the same tune for the last +300k miles with no problems. and the line that I had made was to get me out of BFE with a full load of cattle on. The truck is currently parked until the problems are remedied.
RE: Odd fuel pressure issue - Rawze - 10-25-2021
(10-25-2021 )Lweuve9 Wrote: The truck has been on the same tune for the last +300k miles ...
that does not mean anything.. you need to have that (DE-MANDATE) program reviewed if you give a damn at all about your truck!
MOST ALL DELETE PROGRAMS ARE SEVERELY HARMFUL TO THESE ISX ENGINES!!!!... SEEMS YOU NEED TO WAKE THE HE3LL UP AND SMELL THE FRESH AIR!!!! -- YOUR EQUIPMENT AND ITS LONGEVITY IS DIRECTLY AT STAKE THERE!!!! --- YOU NEED TO KNOW EXACTLY WHAT YOU HAVE AND WAS DONE TO IT!!!... THERE IS NO EXCUSE FOR YOU NOT TO WAKE UP AND SMELL REALITY AT THIS POINT!!!... YOU SOUND EXACTLY LIKE MOST OF THE OTHER PEOPLE THAT COME ON HERE.. AND THEN LEARN LATER... THE HARD WAY.. THAT THEIR ENGINE WAS DOOMED!!!
DOES IT STILL HAVE THE VGT TURBO?... WHAT HARDWARE CHANGES WERE MADE?? .. WHAT WAS DONE TO THE EXHAUST SYSTEMS? .. ETC!.
SEND A COPY OF THE PROGRAM OUT OF THE ECM TO ME AND I WILL REVIEW IT FOR YOU AND TELL YOU EXACTLY WHAT YOU HAVE!!... STOP ASSUMING LIKE A COMPLETE DAMN FOOL! -- YOU NEED TO KNOW EXACTLY WHAT YOU HAVE!!!! .. NOT ASSUME JUST BECAUSE IT SEEMS TO RUN OK SO FAR!. ... AND NO ... IT DOES NOT COST A GADDMAN DIME TO HAVE THIS STUFF DONE!!!... IT IS FOR PIECE OF MIND, AND AN AWAKENING TO WHAT THE H#ELL IS REALLY GOING ON INSIDE YOUR ENGINE, WHAT SOMEONE HAS DONE TO IT!.
AND IF YOUR SO CONFIDENT THAT ITS DONE CORRECTLY THEN YOU WILL HAVE PIECE OF MIND IF IT ACTUALLY WAS... OTHERWISE YOU WILL BE IN FOR A RUDE DAMN AWAKENING JUST LIKE 90+% OF ALL THE OTHER FOOLS WHO CLAIMED THEIR TRUCK SEEMED TO RUN OK... AND LEARNED THAT THE ENGINE WAS EATING ITS OWN GUTS OUT SLOWLY OVER TIME!
Who did the work to it anyways?...
HOW DOES THAT SAYING GO?...
I can lead them to the clean water but if someone chooses to stick their head in the sand, then that is their own stubbornness.
RE: Odd fuel pressure issue - Lweuve9 - 10-26-2021
Ten four