Jump to content

03 Sierra 5.3 died. Can't hear the fuel pump

absinthminded

By absinthminded
in Ask A GM Technician

Recommended Posts

absinthminded Enthusiast

absinthminded

Posted
Posted

Yesterday my truck died while exiting the highway. I tried the key a few times and I could not hear the pump prime. After a tow truck ride home, I pulled the bed. I wanted to do this for a while now. It sucked! 14yr old truck that has lived through Michigan winters its whole life. I only had to cut out one bolt. The other 7 took everything I had to remove them. I got the new pump (Delco from napa). The fuses and relay seem fine. I'm waiting on a buddy to check the fuel pressure and hopefully he can test voltage at the harness just to be sure the pump is bad before I have to wire in the new one.

Is there anything else I'm missing that I should check? Truck has 225k on the clock now and the pump is original. Thanks

absinthminded Enthusiast

absinthminded

Posted
  • Author
Posted

I got a purple, a gray, and 2 black wires at the pump connector. I'm guessing I should see at least 12v at the gray wire? It's powered when primed but is it powered when the key is at aux or just cranking?

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

At that mileage, I'm gonna say you're on the right track.

 

You're lucky you got a Wednesday pump. Mine is starting get loud with just 90k on the clock. I got the Friday-night-before-New-Years TRUCK ...

 

Don't forget, a couple wires are going to be for the fuel gauge. Same wire that supplies voltage during prime is going to be supplying voltage when the engine is running.

barry G Senior Enthusiast

barry G

Posted
Posted

I would wager wires are good.

 

get a whole assembly, it has fresh lid, o-ring gasket.. pump and newer style screen, fuel level sender all at once.

 

about a hundred bucks if you look around.

 

I learned 96-98 had a dramatic update. Avoid "new old stock"

not sure on your 03.

2008 was last worldly update on the pumps (millions of vehicles).

 

my 96 became very powerful. It was comical.

Never been there its whole life...just the new pump.

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

Gotta check 'em anyway. Foolish to install a pump before verifying voltage AND ground at the pump. At this mileage it's a moot point, but you're in there - might as well check.

 

Many a mechanic has been slid by calling a fuel pump, when all it needed was wiring or connector repair.

absinthminded Enthusiast

absinthminded

Posted
  • Author
Posted

It was the fuel pump. My buddy came over and checked voltage at the pigtail well i cranked the engine over. it had plenty of power. The fuel pump ring was rusted the hell and I beat on it with a chisel and hammer And soaked it down with WD-40 and left it overnight. The next day I got it to come off with the punch and a hammer.I went and bought a new ring in the new filler neck because mine was rusty and broken. I went to Napa and got a Delco fuel pump and sending unit I hope it lasts. I wire wheel all the bolts that held the bed down game a good coding of copper antiseaze before I ran them back in. Pulling the bed sucked. 4 wratchet straps and a cherry picker made it possible by myself.

Colossus Senior Enthusiast

Colossus

Posted
Posted

How long have you had that truck? I had a 05 like that for about half a year. (minus those rims) I liked the two tone and it served me well while I had it.

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

It was the fuel pump. My buddy came over and checked voltage at the pigtail well i cranked the engine over. it had plenty of power. The fuel pump ring was rusted the hell and I beat on it with a chisel and hammer And soaked it down with WD-40 and left it overnight. The next day I got it to come off with the punch and a hammer.I went and bought a new ring in the new filler neck because mine was rusty and broken. I went to Napa and got a Delco fuel pump and sending unit I hope it lasts. I wire wheel all the bolts that held the bed down game a good coding of copper antiseaze before I ran them back in. Pulling the bed sucked. 4 wratchet straps and a cherry picker made it possible by myself.

 

Glad you got her figured out and fixed! :thumbs::cheers:

 

Yeah, gotta love rust. Everything I touch is exactly like that. Torches and hammers are common "hand tools" in the Northeast here. :lol:

mjoekingz28 Enthusiast

mjoekingz28

Posted
Posted

At that mileage, I'm gonna say you're on the right track.

 

You're lucky you got a Wednesday pump. Mine is starting get loud with just 90k on the clock. I got the Friday-night-before-New-Years TRUCK ....

 

So the UAW got a head start on the holiday?

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

Apparently. Everyone must've been drunk on ball joint, strut, brake, and interior day.

Hoginedgewood Enthusiast

Hoginedgewood

Posted
Posted

my last fuel pump went bad at the output, the metal pipe that is part of the pump exiting the tank. it rusted out. ten Cincinnati winters. I'd concider undercoating the top after its all together. and put some silicone grease in the connectors to keep out moisture.Not caulk.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • CamGTP
      Gas Prices

      By CamGTP · Posted

      Paid $2.72 for E85 today.
    • Atlas
      Gas Prices

      By Atlas · Posted

      Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • scotthvac.net
      2022-24 halogen - led grille swap

      By scotthvac.net · Posted

      2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers
    • davester
      Replacement Radiator

      By davester · Posted

      And use RA's 5% discount code if you buy from them.  google for the code, one is always available.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...