25 psi after swap

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Jackslaw64

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Sorry if this is a redundant post, I've been driving my 5.3 nv3500 swapped 90 Sierra for about 3 months now. I finally ironed out the OBD2 sensor and realized I had two codes, P0174 and P0171. I bought a fuel pressure gauge and read 25 psi at the fuel rail, key on engine off. I tested for vacuum leaks, and couldn't find any. I had a small leak at the C5 regulator which I fixed, the guy who installed the AN fittings (me) didn't do a good job tightening them, go figure. I tested again, and got 25 psi still. The pump (ep381) is brand new and was replaced when I swapped the engine. The regulator is brand new too, so I'm lead to believe it's one of those, but before I bought a regulator, I wanted to hear from the experts.
 

Supercharged111

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When you say C5 regulator, you mean filter/regulator right?

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0xDEADBEEF

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Were you the guy that had the problems getting it started and it turned out to be stuck injectors?

The fuel filter is pretty cheap and easier to swap, so I guess I would start there.
 

Jackslaw64

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Were you the guy that had the problems getting it started and it turned out to be stuck injectors?

The fuel filter is pretty cheap and easier to swap, so I guess I would start there.
I was haha, glad that's behind me for sure, I figured I'd start with the filter just hate that I could've bought a bad one
 

Jackslaw64

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Replaced regulator and still have 25psi, leaning towards it being fuel pump now, just don't want to have to drop this fuel tank in a dorm parking lot again.
 
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