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

Help! High fuel pressure?

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Old Aug 30, 2014 | 12:07 PM
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Default Help! High fuel pressure?

OK so I've been chasing a load up problem, after going thru my coils, wires and plugs I figured I better check fuel pressure, went down to a buddy's shop, hookup up a gauge and primed the pump.....95 psi!! Started the car and it dropped slightly, rev the car and it drops slightly. Even tried 2 different gauges. Running a stock LS1 pump and a Corvette style filter/ regulator, help!!

Last edited by sumnerslayer; Aug 30, 2014 at 12:13 PM.
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Old Sep 4, 2014 | 08:42 PM
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Not one reply? I installed a new Vette filter/ regulator and still pushing 85-90 psi, I blew air into the tank thru the return line, there was some resistance but it took air, how free flowing should it be? How does the return in the pump work?
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Old Sep 4, 2014 | 09:03 PM
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Pretty sure the return line should be free-flowing. You could always pull it off the regulator and run it to an open bucket and see if the pressure comes back to normal...
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Old Sep 4, 2014 | 10:30 PM
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Might give that a shot tomorrow but at this point I'm pretty convinced the problem is in the pump, I have a hard time believing the line is plugged or kinked, system isn't that old and problem just randomly occurred, I really don't wanna drop the tank because of the new exhaust, (all 1 piece pipes) so I guess I'll have to put in a trap door
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Old Sep 5, 2014 | 06:37 AM
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The problem will not be the pump.

Draw a schematic of exactly how you have the system configured.

Sounds like either a blocked return, or you have plumbed the regulator wrong ( or if it is adjustable, adjusted it wrong )

or finally a faulty reg.
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Old Sep 5, 2014 | 07:17 AM
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Stock LS1 pump you say? Did you remove the stock regulator from the return?
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Old Sep 5, 2014 | 04:49 PM
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Stock LS1 pump, a 3/8 feed line coming into the Vette filter/ regulator, a 3/8 going back to the pump hooked to the port marked "R". I know the plumbing is right because I didn't not have high pressure before this issue, the pump has a regulator built in, it is still in there, I've read if that fails its cheaper to just replace the whole pump assembly, I know the pump is fine, its obviously pumping fuel lol
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Old Sep 7, 2014 | 08:32 AM
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Did you remove the internal regulator in the factory fuel module? If not you are trying to run it through 2 regulators.
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Old Sep 7, 2014 | 12:35 PM
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Removed the internal one last night, I haven't had a chance to test pressure yet, chance my inline one is damaged now with seeing 90psi for a bit?
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Old Sep 7, 2014 | 07:52 PM
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It's probably OK.
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Old Sep 9, 2014 | 07:36 AM
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Threw a gauge on it yesterday and now its sitting at about 60-62 psi which I believe is acceptable, thanks for the replays guys!
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