Fuel pressure regulator or fuel pump?

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blackhawk17

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So, we're taking about a 2000 3500 454, and it has hard starts, or what I'd call failed starts.

I read on another forum about basically the fuel system losing its prime when the vehicle sits, But I think this was on a different vehicle. Their suggestion was to turn the key to kick on the fuel pump, prime the system, then turn it back off again. Turn the key again, let it prime, and see if it starts.

Well I tried this, and it appeared to help. I'm thinking also that sitting on an incline makes the problem worse.

So, the question is in the title. Do these trucks have fuel pressure regulators that need to be changed, or do I need a fuel pump?

Another issue that may be unrelated, or it may be a symptom of this same issue, is that once the engine is warm sometimes I'll get a rough idle and a little hesitation on take off. I just changed the fuel filter, plugs, wires, cap, rotor, and air filter.

Thanks for the advice.



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df2x4

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I believe the Vortec trucks have a regulator that's part of the injector system under the cover, however I've never heard of one failing. It's probably your fuel pump in the tank unfortunately if you've already changed the filter.
 

Supercharged111

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Injectors and regulators are the cause here. I did a regulator on mine and it didn't really help. Injectors are next as I need them for the blower anyway. I've tried priming more than once and it's still garbage. Same with the LT1 in my Camaro. Always been a hard starter warm and both engines are notorious for crap injectors.
 

my name is alex

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I've had hard starts, only when warm, with my 454 since I bought it a few years ago. From everything I researched, I'm thinking it's the FPR, which is not easy to get to on our engines, unfortunately.

She cold starts like a champ every time. Warm starts can take 3-6 seconds of cranking. I'd like to have the injectors replaced when I get the FPR done, but than you're talking quite a bit of cash for good injectors.
 
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Supercharged111

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Seems you missed the part where FPR alone did nothing for me. Same amount of digging to to FPR as injectors. . .
 

my name is alex

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Seems you missed the part where FPR alone did nothing for me. Same amount of digging to to FPR as injectors. . .

Assuming your remark is aimed at me, nope, I didn't miss a thing. From what I can tell researching my particular warm start issues, I'm hoping it's just the FPR. Injectors will be the same amount of digging, but considerably more cash to replace with a good set. Could I still end up with the issue due to my injectors - of course, it's a possibility.

This problem has been solved by replacing the FPR alone, in some trucks.

That being said, I would like to have the injectors replaced as well, and so I may just have it all done at once depending on whether I feel like shelling out all that cash. My concern then will be whether it ends up being a fuel pump issue and I end up still having problems...though this seems unlikely to me.
 

blackhawk17

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So what I'm hearing is maybe fuel pressure regulator, maybe injectors, maybe fuel pump.

I'm going to throw a couple more symptoms in to see if I can narrow it down some more:

After the engine has warmed up pretty good, I'll feel a little hesitation at take off. After even longer it turns into a miss, and it will idle rough and the exhaust smells awful. I videoed the exhaust at idle today when it was doing this and there was a faint black tint to the exhaust.

I noticed not long after buying the truck that the bumper was covered in oily splotches, which I assume is some kind of soot from the exhaust. We put a towel next to the exhaust pipe and held idle at about 2500 rpm, and it spewed a bunch of oily soot in very little time.

My buddy thought that it just needed some good driving to clean out since it was owned by an old man and he probably just putted around. But I'm thinking it's a symptom to a bigger issue.

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meterman

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Is the mileage crap it might be way rich due to bad injectors and that will jack the cat up and cause a smell , what do the plugs look like sooty smell like gas or oil up


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east302

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Have you done a fuel pressure test? Not sure what the specs are for a 454, but that could help narrow down a pump vs regulator or leaking injector issue.


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