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2002 GMC 3500 Sierra Crew Cab Dually, 8100 Gasser.
About a year ago once in a while it wouldnt fire on the first attempt to start it. Its always started right up before.
Its gotten worse and its 98 % of time now it wont fire up first try.. The fuel pump failed a few years back and was replace with a new GM pump. Im good about changing the fuel filter and it has a new one now. No fuel leaks anywhere I can find.
Its fuel injected and I know it needs quite a bit of fuel pressure to run.
After the truck was sitting I loosened the fuel line at the motor and I would guess a small amount of fuel under pressure should spray out, and that the motor to fire right up needs pressure in the line.
So Im thinking there is a one way valve somewhere between the out put line of the fuel pump and the motor.

My question, is that true there is a valve and where is this valve that lets fuel under pressure in but not back to the tank.
 

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Toxic Masculinity
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The check valve is in the pump. Turn the key to the "run" position (no starter motor) for three seconds > Turn key to the off position > Start normally > if it cranks right up it's probably a bad/stuck check valve.
 

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Discussion Starter #4
QUOTE="Graystone, post: 6115174, member: 6102"]
Check your fuel pressure regulator. If you pull the vacuum line and fuel comes out it's bad.

About 2.5 years ago the truck all of a sudden would just stop running. You would hit the key and it would fire right up, I just sold a house so I had some cash and that same day brought it to this shop in Hemet Ive used before. It ended being the fuel pump relay was cooked, It was replaced and very shortly after this problem started occurring.
I checked out a You Tube vid on checking the fuel pressure regulator but couldnt find one for a 8.1 gas motor, only showed a 5.8 L Chevy.
So I went out and removed the black plastic bezel on top of the motor. The nut on the top left wouldnt spin off and had to remove the entire stud, No biggie but of course something had to f with me, : ) I found what I believe is the regulator, It looked a lot like the regulator in the vid but it attached different, There was no metal snap ring that went around the entire regulator to remove. I did see a round snap ring that you could compress and remove the guts of the reg like I saw in the video. I pulled the vacuum line off and didn't see or smell any fuel. I just left it at that.
Does what Im describing sound like the regulator?
I will have to look into that some more.



QUOTE="RedXray, post: 6115198, member: 3667"]
The check valve is in the pump. Turn the key to the "run" position (no starter motor) for three seconds > Turn key to the off position > Start normally > if it cranks right up it's probably a bad/stuck check valve.


Thanks for the lead RedXRay. I thought the fuel pump on that year didnt start working until right after the motor fired up. Ive never just turned the key on and can even hear the fuel pump.
On My 2000 GMC 3500 Sierra Crew cab short bed dually I remember you could hear the pump running while idling. Is this check valve assembly all part of the pump??

Sometimes I have more money then time and a 10 months ago the truck needed 4 02 sensors replaced and I had the same shop that I have used before do it. I asked them to look into this starting issue. They said it would be around $600 to fix and now that Im thinking about it pretty sure he said the check valve and its in the tank.
Im self employed and due to this corona virus, this is not one of those times I have more cash then time. I called the shop and was asking about getting the truck in to fix the no start 1st click issue and was trying to get him to refresh my memory of what was wrong and where the part was because i couldn't remember. But the guy I was talking too wasnt going for telling me. I dont blame them. 3 months ago the same truck needed a radiator, I know they do good work and their not cheap. I figured they would know where the buy a better built radiator then any I could get from Auto Zone or Oreillys etc. I could have got a real good one from the dealer but an AC Delco was $1000. just for the radiator. The shop sold me the radiator for $420.00. I was good with it.
I really did feel like cheap bastard doing that but money was tight.
So as mentioned they wernt handing out any advice.





https://www.oreillyauto.com/
 

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Toxic Masculinity
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You could save a ton if you wrench on the truck yourself. I installed a new large Sunbelt 34" core radiator for $90 just as good as the Delco brand if not better. AC Delco does not manufacture parts anymore they use other companies items and re-box with their brand name. AC Delco never made o2 sensors most are Denso sensors and you guessed it re-boxed under the Delco name. I payed $23 each for new o2 Denso sensors and installed in less than 30 minutes including getting the truck in the air.
 

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I thought the fuel pump on that year didnt start working until right after the motor fired up. Ive never just turned the key on and can even hear the fuel pump.
On My 2000 GMC 3500 Sierra Crew cab short bed dually I remember you could hear the pump running while idling. Is this check valve assembly all part of the pump??
The check valve is in the fuel pump module assembly that sits in the tank. It basically just keeps the lines full, not highly pressurized, so the pump comes on before you start, builds pressure, and then engine starts. Without the check valve, the pump could be programmed to run longer and still start in a normal timeframe, but it increases the wear / failure rate of the pump.

It's possible on the first fuel pump replacement you didn't get the updated fuel pump part yet, but there is one now that works better than the original did. If the electrical connector for the fuel pump module wasn't changed, I'm pretty sure the part wasn't the updated one, but you'd probably have to drop the fuel tank to see that.

Pumps tend to get noisier as they age, it's possible your pump was quiet enough not to be noticed.
 

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Toxic Masculinity
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The check valve is in the fuel pump module assembly that sits in the tank.

....the pump could be programmed to run longer and still start in a normal timeframe, but it increases the wear / failure rate of the pump.
Check valve as been addressed above.

You can't extend the fuel pump prime duration with a P01 (0411) PCM which I'm pretty sure the 2002 8.1 runs. [email protected] said they were looking for a patch for the pump prime duration issue but never followed through.
 
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