Fueling & Injection Fuel Pumps | Injectors | Rails | Regulators | Tanks

Fuel Delivery Problem

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Old May 17, 2010 | 01:54 PM
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Default Fuel Delivery Problem

Every time I have a problem I bring it here and you guys solve it for me so heres the next one haha.

My truck will idle fine and is set a 58 psi. I've not really looked at the gauge at WOT but it seemed like when i would rev it sitting still it didnt fluctuate much (i need to verify this still) but when I drive it down the road it revs and then bogs out. When i give it full throttle it goes ok but when I try to stay at a steady constant speed it doesnt respond / cuts out. It seems like its running rich too. I'm on my second set of plugs and it only has about 2 hours of run time. Its a project truck.

Here is the list of mods:
4.8L truck engine - LS1 intake manifold - 28.8 Injectors - Returnless style Rail - Fuel Pressure Regulator w/ Return - SLP shorty headers - Comp 220/222 110lsa cam - SLP valve springs - No Cats - Dual Magnaflow bullet mufflers - No rear 02 sensors - Tuned PCM - Removed EGR - Removed EVAP - Cone filter straight off the MAF that is straight off the Throttle body

I also have a fuel cell with a MSD 2225 external pump. Upon further reading online I'm not sure if it puts out enough PSI. I just ordered a Walbro 255 pump because I'm starting to think it isnt getting enough fuel under load. Does this sound right or should I be looking into other areas to fix it?
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Old May 17, 2010 | 04:54 PM
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you need a gauge on it to see if you are getting consistent 58psi. How do you have a reg. plumbed and a return line with returnless rails?? More info please.
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Old May 17, 2010 | 06:26 PM
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I put a professional products regulator on my firewall. It has the line coming from the pump then out to the motor and on the bottom has a return line going back to the tank. I have a gauge on the regulator and at idle and while i rev it the pressure stays around 58.
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Old May 18, 2010 | 07:48 AM
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Regulator is on the wrong side of the rail[s].
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Old May 18, 2010 | 05:14 PM
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So i need to get new rails? The one im using now is a stock rail from a car (returnless style). (my truck was originally a return style truck intake)

So basically i need to get some new rails with a return?

Does it need plumbed like this:

Fuel pump to fuel filter to fuel rail in to fuel rail out to fuel regulator in side to fuel regulator out side back to tank?

What would i do with the extra return fitting on the bottom of the fuel pressure regulator?
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Old May 19, 2010 | 08:42 AM
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anyone?
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Old May 19, 2010 | 06:44 PM
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Does anyone know if i need a new fuel rail with a return? Do I put the fuel pressure regulator after the return? What do i do with the fitting on the bottom of the fuel pressure regulator. Does anyone have a diagram of how it needs to be plumbed? I thought it had it right.
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Old May 20, 2010 | 10:49 AM
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The proper way is to do flow through rails and the regulator on the return side. But you really need to know what your problem is first. are you dropping pressure under throttle?.....and just looked up that pump and its max pressure rating is only 40psi you are prob over taxing the pump.
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Old May 20, 2010 | 09:30 PM
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The gauge is on my fire wall so i cant see it driving down the road but during revs it drops down to about 50-52 and then back up to 58.

I just need to know if i need different rails or not. It seems the same to run it this way opposed to a return style rail to the regulator.

The new fuel pump should be in tomorrow so I'll put that in and scan it to see what i come up with. If anyone comes up with any ideas please post it up. Thanks a ton!
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Old May 21, 2010 | 07:25 AM
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"What do i do with the fitting on the bottom of the fuel pressure regulator."
The bottom port is the return to tank line.
The side[s] ports are from the rail.
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Old May 21, 2010 | 11:16 AM
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Originally Posted by Old Geezer
"What do i do with the fitting on the bottom of the fuel pressure regulator."
The bottom port is the return to tank line.
The side[s] ports are from the rail.
Shouldnt it work how its set up now though? I'm just trying to find out if its plumbed right. I know the pump is not correct and I'm waiting on the 255 to come in.
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