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Slow bleed down adjustable fuel pressure regulators that act like a check valve?

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Old 02-19-2016, 09:36 PM
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Default Slow bleed down adjustable fuel pressure regulators that act like a check valve?

Which adjustable regulator also acts like a check valve? I have to prime the key 3-5x to get the truck to start without extended cranking. I've tried different pumps, I do not think its the pump. It might have something to do with the Walbro 450 having to fill large -8 lines but I also think it might be the regulator.
Old 02-19-2016, 10:12 PM
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Regulators wont hold pressure in lines.....my big ***** looking aeromotive regulator bleeds off just as my magnafuel did

If you take one apart youll see rhere is nothing to keep pressure there youre only restricting the flow.

Even big single pumps bleed off pressure
Old 02-19-2016, 10:13 PM
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Im in the same boat aswell with this. I run an aeromotive 340 intank and have the aeromotive boost referenced regulator and i most of time have to prime mine a couple times aswell and truck fires right up. Otherwise a single prime and flip of the key turns over numerous times before firing. Ive wondered about a check valve aswell for this setup!
Old 02-20-2016, 08:08 AM
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the fuel pressure probably bleeds back through the pump and not the regulator, a one way check valve in the supply line could solve it but would probably be a restriction
Old 02-20-2016, 09:49 AM
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My fuel lab even states in the info it comes with that its not designed to hold pressure when pump is off.

On that note though you shouldn't have to prime it that much. What pump do you have? Sounds like it's draining back.
Old 02-20-2016, 09:36 PM
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Originally Posted by Mean Green z28
the fuel pressure probably bleeds back through the pump and not the regulator, a one way check valve in the supply line could solve it but would probably be a restriction
Magnafuel told me to put low cracking pressure check valves between the fuel rails and the regulator. So if you have checks that take 1/2 psi to open, they will maintain 1/2 psi when the pump is off.
Having no air in the system and slight pressure will give instant full pressure and starts the same as stock, instead of having to refill and then pressurize a system that has drained because of the aftermarket regulator.
Old 02-21-2016, 08:50 AM
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If I prime mine it goes up to set pressure (55psi) within 1 second and will hold 20-30psi for an hour or so. Walbro 400s and aeromotive regulator.
Old 02-21-2016, 10:05 AM
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I doubled my key on prime time from 2 seconds to 4 seconds and it took care of mine. I'm not sure if all ECUs have that option.
Old 02-21-2016, 10:44 AM
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I can't find it in HP Tuners with my 2002 OS. Am I looking in the wrong place?
Old 02-21-2016, 11:09 AM
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I have a gauge for that
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It's in there, mine is an 02. I have mine set for .25 seconds I think


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