Author Topic: Fuel pressure for LS:  (Read 1068 times)

Offline Stewart G Griffin

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Fuel pressure for LS:
« on: October 22, 2021, 03:12:57 AM »
How/where is the fuel pressure regulated on an LS engine?

Offline dusterdude

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Re: Fuel pressure for LS:
« Reply #1 on: October 22, 2021, 04:14:13 AM »
What year and model engine?

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Offline VileZambonie

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Re: Fuel pressure for LS:
« Reply #2 on: October 22, 2021, 07:47:50 PM »
Fuel rail, but yes, speak in specifics. YMM
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Offline Shifty

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Re: Fuel pressure for LS:
« Reply #3 on: October 23, 2021, 10:26:53 AM »
What they said, the fuel system is either returnless, and dead-heads at the rail, or has a return line.
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Offline Stewart G Griffin

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Re: Fuel pressure for LS:
« Reply #4 on: October 23, 2021, 11:58:59 AM »
Not sure about specifics.  i meant in general.

Let's say for a LS3 crate engine.


Actually, why don't we just discuss both styles----return and returnless.

Offline dusterdude

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Re: Fuel pressure for LS:
« Reply #5 on: October 23, 2021, 02:38:39 PM »
Iirc,they are around 48 psi

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Offline Shifty

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Re: Fuel pressure for LS:
« Reply #6 on: October 23, 2021, 04:35:00 PM »
This is an example of an LS3 car (2011 Camaro):

stats for fuel pump is 34 gal/hr @ 86 psi. 

Not sure if that tells you anything relative, but that's what I've got at work.
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Offline Stewart G Griffin

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Re: Fuel pressure for LS:
« Reply #7 on: October 24, 2021, 10:46:34 PM »

Offline ehjorten

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Re: Fuel pressure for LS:
« Reply #8 on: October 25, 2021, 08:59:30 AM »
Early LS engines have a pressure regulator on the rail, usually the LH rail and a return line back to the tank. There is the Corvette version that has the fuel pressure regulator built into the fuel filter, with a return line, and then the later model ones have a fuel pump module in the tank with the return directly in the tank and no return line.
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Offline Stewart G Griffin

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Re: Fuel pressure for LS:
« Reply #9 on: November 25, 2021, 08:09:47 PM »
Early LS engines have a pressure regulator on the rail, usually the LH rail and a return line back to the tank. There is the Corvette version that has the fuel pressure regulator built into the fuel filter, with a return line, and then the later model ones have a fuel pump module in the tank with the return directly in the tank and no return line.

So really, the computer, fuel rail, and injectors don't care or know about the fuel pump;  As long as there is 58lbs +/- 2lbs at the injectors it's all good?

The pump could be an out-of-tank, inline deal of questionable offshore origins and as long as it's putting out around 58lbs, it's all good?

Offline frotosride

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Re: Fuel pressure for LS:
« Reply #10 on: November 27, 2021, 07:38:45 PM »
Yes, this was a the only undesirable things for an LS. The PCM doesn't account for fuel pressure. It only assumes there's 58psi. Any pump will get you running as long as it can produce 58psi and I wouldn't recommend anything under 200lph. I do believe 155lph was standard. But it kept the injectors almost maxed out.
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