6.0 Fuel Pressure drop

BufertSS

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So I have tried about 10 different things to fix my fuel pressure and have spent countless hours of research. I need your alls help.

I have a 2006 f250 6.0L. I am running a AD 150 feeding a stock pump, with a RR kit. I have 170 injectors (installed by previous owner) SCT tuner with a Extreme tune by Innovated Diesel.

I am holding good pressure (62 PSI) at idle and if I keep from going full throttle I can maintain about 60 PSI up to cruise and just driving around. When I go WOT pressure will drop below 40 if I let it. I usually let off to try to protect my injectors. I am taking my pressure readings from the regulator on the RR kit. I recently replaced my stock fuel pump about 3 months ago. I have been getting water in fuel light and been draining it every time I get that light. But after I installed the AD150 It has seemed to not come back. I am just not sure if maybe reading the fuel pressure from the regulator could be giving me this drop or what. I am at a loss. Any suggestions would be helpful. Thank you.
 

BufertSS

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Negative. I have Pulled the Tank Twice now. First time to check if I had those Filters and Second to Install the AD150. I even did my best to clean out and sand and what not that may have been in the tank from before.
 

Strictly Diesel

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Reading from the regulator is the RIGHT place to do it.

What regulated return?

Factory Secondary Filter Bowl still in place?

Still have a filter in the secondary bowl (if yes to above)?
 

BufertSS

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Yes I still have the Factory Secondary Filter Bowl. I have replaced both lower and upper fuel filter bowls at every oil change (5000 Miles). I just changed the fuel filters literally 3 days ago when I installed the life pump
 

Strictly Diesel

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Kinda figured...I take it they can't tell you why you are having the problem?

Do you have a set of "soft jaw" or "hose crimp" pliers, the type that won't damage a rubber hose?
 

Strictly Diesel

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Follow the return hose after it leaves the block on the side of the filter bowl. There should be a section of factory hose in the return line that you can crimp with soft jaw pliers. Crimp it "mostly" closed and see if the pressure drop is the same under load. This MAY raise your idle fuel pressure, depending on how much you crimp the hose, just keep the idle pressure below say 70-75psi.

Let me know what it does.
 

BufertSS

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So at idle I had little to no change, maybe 1 or 2 PSI. Ill have to try tomorrow under a load to see what happens.
 
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BufertSS

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If I am following you, Are you looking to see if its the fuel bowl/Stock Regulator housing that is the source?
 

Strictly Diesel

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If you crimp the line totally closed, the pressure should go up more than 1-2 psi. It should go up to "pump max" pressure...and I would expect 90psi+.

Ideally you shouldn't need to crimp it 100% closed, just enough to raise the pressure some.

If crimping the line 100% closed doesn't increase the pressure very much, and driving it with the line crimped 100% closed doesn't fix the pressure drop issue, you have a FUEL DELIVERY (VOLUME) PROBLEM that needs to be tracked down.
 

Strictly Diesel

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I'm just trying to figure out where the problem is, without blaming any particular part of the system first. Easy to throw a larger pump at the problem, which may very well solve it by brute force, but 170s shouldn't need it.

That said, any chance the injectors aren't really 170s???
 

BufertSS

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Ok so got it crimped to 75 PSI. Ran it under load and had same issue as stated before. I might have been able to get closer to WOT but not by much
 

BufertSS

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The chances of them not being 170s is possible. The list i received from the shop that installed them actually said 70HP injectors. Which with what i looked up my best guess was 170 injectors
 

BufertSS

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Ideally you shouldn't need to crimp it 100% closed, just enough to raise the pressure some.

If crimping the line 100% closed doesn't increase the pressure very much, and driving it with the line crimped 100% closed doesn't fix the pressure drop issue, you have a FUEL DELIVERY (VOLUME) PROBLEM that needs to be tracked down.[/QUOTE]

So at this point, you think I need to be looking for a bigger pump of some sort. Do you think ******** the fuel bowl may fix this problem?
 

Strictly Diesel

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So the fact that the pressure situation didn't change much tells me that you have a supply volume issue, or injectors that are significantly larger than you think. Since I believe you previously said that you replaced the stock fuel pump, and you are supplying that stock pump with an AD150...AND ASSUMING THAT BOTH PUMPS ARE WORKING CORRECTLY...you should be good up closer to a 190cc injector with a hot tune.

Since it looks like the problem existed before you changed the OE pump and before you installed the AD150, and that you did both of those trying to fix the pressure drop with no help, I'm leaning toward "too much injector for a stock pump" being your issue.

I don't see a bowl ****** fixing the problem by itself, as the bowl isn't the problem.

That AD150 should be just fine feeding an aftermarket pump like a Fuelab or our Dual Bosch OE pump setup. Ultimately you need your high pressure pump to be capable of moving more volume than you have now.
 

BufertSS

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So the fact that the pressure situation didn't change much tells me that you have a supply volume issue, or injectors that are significantly larger than you think. Since I believe you previously said that you replaced the stock fuel pump, and you are supplying that stock pump with an AD150...AND ASSUMING THAT BOTH PUMPS ARE WORKING CORRECTLY...you should be good up closer to a 190cc injector with a hot tune.

Since it looks like the problem existed before you changed the OE pump and before you installed the AD150, and that you did both of those trying to fix the pressure drop with no help, I'm leaning toward "too much injector for a stock pump" being your issue.

I don't see a bowl ****** fixing the problem by itself, as the bowl isn't the problem.

That AD150 should be just fine feeding an aftermarket pump like a Fuelab or our Dual Bosch OE pump setup. Ultimately you need your high pressure pump to be capable of moving more volume than you have now.
\

Well Looks like Ill look into that now haha Thanks for the help
 

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