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  #16  
Old November 8th, 2017, 18:50
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Re: New fuel pump, new regulator, still has fuel pressure issue..

You have a fuel leak. It should hold pressure for hours. Try clamping the return line and running the test again.If it holds, the leak is on the return side. if it drops, its on the pressure side.
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  #17  
Old November 8th, 2017, 18:50
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New fuel pump, new regulator, still has fuel pressure issue..

https://youtu.be/VqjuAqeMZWA

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  #18  
Old November 8th, 2017, 19:04
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by four_shot View Post
You have a fuel leak. It should hold pressure for hours. Try clamping the return line and running the test again.If it holds, the leak is on the return side. if it drops, its on the pressure side.
So I did as you suggested I clamp the return line and Prime that the system in gauge shot up to 60 because the return line is Vise grip and it slowly bled down to 40 mid-30s but stops right there which is where it should hold anyway so it isn't bleeding off at the rail since it drops from 6230 correct it only drops from 60 to 30 because it is over pressurized correct

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  #19  
Old November 8th, 2017, 19:06
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by four_shot View Post
You have a fuel leak. It should hold pressure for hours. Try clamping the return line and running the test again.If it holds, the leak is on the return side. if it drops, its on the pressure side.
WOW.. voice to text butchered that! I clamped it at the return line.. i primed it... It shot to 60 and lowered to 30-40 ish, and stays there. So im wrong for thinking the rail is the culprit correct? It drops 60 to 30-40 because 60 is over pressure ised. Am i thinking logically?


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  #20  
Old November 8th, 2017, 19:07
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Leaking down that fast does not sound reasonable for an injector. Or several. If it were injectors your oil should be full of gasoline by now. It should be simple enough to check the oil just with the dipstick. Maybe give it a good sniff too. If still in doubt you could change the oil. Then try to light the drain pan. Well, maybe not...

I can't imagine the vehicle would even run well with injectors that didn't shut down.

I think revisiting the tank end of things is the best bet right now. The suggestion of trying to run the pump assembly outside of the tank is a reasonable one, if you can figure out how to do it safely.
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  #21  
Old November 8th, 2017, 19:08
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Re: New fuel pump, new regulator, still has fuel pressure issue..

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Originally Posted by Anak View Post
Leaking down that fast does not sound reasonable for an injector. Or several. If it were injectors your oil should be full of gasoline by now. It should be simple enough to check the oil just with the dipstick. Maybe give it a good sniff too. If still in doubt you could change the oil. Then try to light the drain pan. Well, maybe not...

I can't imagine the vehicle would even run well with injectors that didn't shut down.

I think revisiting the tank end of things is the best bet right now. The suggestion of trying to run the pump assembly outside of the tank is a reasonable one, if you can figure out how to do it safely.
How do i safely do that?

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  #22  
Old November 8th, 2017, 19:18
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Ask BCKNBLK how he went about it. Or how he would go about it if he were to do it again.
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  #23  
Old November 8th, 2017, 19:32
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Re: New fuel pump, new regulator, still has fuel pressure issue..

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Originally Posted by BCKNBLK View Post
Drop the fuel tank and give that assembly in there a very good look-over. You are describing the exact problem I had several years ago. Turns out the fuel pump/filter/float assembly had a leak on it. The pump worked fine, but there was a leak on the unit itself and was leaking fuel right back into the tank. Finally discovered this after taking it out again, and priming it off the vehicle. It started pissing fuel back into the tank. Thats where my pressure was going. Dropped in a brand new assembly (brand new), re-installed the tank, etc. Ran like a champ.
How would one go about this? I'm under my jeep with the assembly out and a cup of gas lol...

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  #24  
Old November 8th, 2017, 19:48
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Re: New fuel pump, new regulator, still has fuel pressure issue..

I'm thinking there is an internal leak at the fuel pressure regulator. I just haven't had enough of them apart to know what's missing. He's got both o-rings on the regulator. I thought there was a screen that spaced the small o-ring further into the socket. but that may be on a GM system.

I'm at a loss.





Edit: the screen I was thinking of is found on the Chevy Vortec 4.3's. (so it doesn't apply here)
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Last edited by four_shot; November 8th, 2017 at 20:13.
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  #25  
Old November 8th, 2017, 19:54
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Re: New fuel pump, new regulator, still has fuel pressure issue..

Quote:
Originally Posted by Intellect View Post
How would one go about this? I'm under my jeep with the assembly out and a cup of gas lol...

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I'd try a clean drain pan and enough gas to submerge the filter sock.
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  #26  
Old November 8th, 2017, 20:11
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New fuel pump, new regulator, still has fuel pressure issue..

Low and behold i have progress who is still awake!? First a question... What SHOULD the system hold psi wise, and over what time period....instead of losing INSTANT pressure, it went fron 30 to 20 ish when i shut her down, than over the past half hour its down to 15... Now down to 12... I THINK it kight hold 12, ill explain what i found later on, but for now need the pressure answers please... I promise you WILL laugh ..

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  #27  
Old November 8th, 2017, 20:38
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New fuel pump, new regulator, still has fuel pressure issue..

The little rubber hose at the bottom was leaking, i sat the sock filter guy in a cup of gas, ran the pump, and watched as gas trickled out of the bottom of the hose.... I added a better hose clamp and actually used two... It still lighlt lighty leaks just enough to notice its wet, is that normal? The hose and clamps are fine, and it holds 25 psi after shut down fine, than 15, than an hour later drops to 9/10 psi... SOO


, the 30psi during running to 0psi when switched off, was ALL THANKS TO A HOSE CLAMP!


IS IT ok that it SLOWLY bleeds down to 9/10psi or do i have a second issue at hand?

Should i keep buying different hose clamps till one leaks 0%? Lol

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  #28  
Old November 8th, 2017, 20:41
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New fuel pump, new regulator, still has fuel pressure issue..

To clarify... Jeep had 30psi cranked, 0psi as soon as it was switched off.


The fuel pump in cup of gas

When cranked would leak, when switched off would leak

I put new hose clamps

Now when cranked it DRIPS ever so barely, and when switched off it leaks ZERO and pressure dies SLOWLY from 25 to 9/10 over an hour of time.

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  #29  
Old November 8th, 2017, 20:48
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New fuel pump, new regulator, still has fuel pressure issue..

Im just being super nervous now that i found out the flowing hose was the issue, this clamps a LOT tighter, im just super anxiety over the fact ANY gas leaks from under hose LOL.

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  #30  
Old November 8th, 2017, 22:01
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Re: New fuel pump, new regulator, still has fuel pressure issue..

The 30 psi is about right.

The leaking down is still not right. But, it is nice to see that you have made progress on that front.

A couple of details regarding that hose. First, make sure it is the correct type of hose. It should be SAE 30R10. If in doubt, you should be able to get that from a Napa auto parts (Linky: http://www.napabeltshose.com/~/media...hose.pdf?la=en )

Second, get yourself some fuel injection hose clamps. I don't know that they are generally required inside the tank, but given the situation I would not hesitate to spend the $5 or so to get the best clamp possible for the job. FI hose clamps should do a better job.

Once you have things under control at the sending unit/pump assembly, if you still have a leak down situation, then go back to clamping off the fuel line to see if you are losing pressure at the injectors.

You may have more than one issue at play here.

ETA: Thank you for posting up your progress on the problem. All too often solutions are proposed but no follow up ever happens, and thus nothing is learned by the rest of us. And I am sure it is often really simple stuff, like that leaking hose, and no one wants to share something that others might think is stupid. I am certainly not laughing at you for a leaking hose that can't be identified without taking things apart and testing them outside their normal environment. Thank you.
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Last edited by Anak; November 8th, 2017 at 22:05.
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