Think I might need a fuel pump?

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by workman482, Mar 28, 2013.

  1. workman482

    workman482 New Member

    Well, I'm loving my new truck but it has had a starting, and no power problem since I bought it a couple of weeks ago. The previous owner knew about the problem and even uad the fuel pressure regulator replaced in hope that it would fix the problem.
    You can hear the fuel pump kick on and run for a few seconds when you turn the key on, but most of the time the truck will not start until the second attempt. It also feels like it has very little power on take off. If I let it sit for a few minutes after I shut it off and depress the Schrader valve on the fuel rail I get nothing. If I do it with the engine running then obviously I get fuel. Im thinking the check valve in the pump assembly is toast and not allowing any fuel pressure to remian in the line.
    What do you guys think? Oh yeah, almost forgot. The fuel filter has been replaced also.

    The truck is a 2003 Silverado 2500HD 4wd with a 6.0L and 5 speed manual.
  2. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Run a fuel pump pressure test. Leak down and operating pressures.
    You should be able to get the pressure test set from Auto Zone
    The test will verify if you have a pump problem.
  3. workman482

    workman482 New Member

    Yeah, I'll run by there after work to see what the pressure is reading. I'll go ahead and order the pump from Amazon as they have them for at least $100 less than the big name parts stores. If it turns out not to be the pump I can just return it.
  4. Skippy

    Skippy Member 2 Years 100 Posts

    Yeah, based on what you've done (no pressure at the schrader valve a few minutes after priming) you've basically perfomed a leakdown test.

    You could confirm it with a gauge connected to the valve watching it prime, and then monitoring to see if it holds pressure. I strongly suspect, as you obviously do, that your fuel pump is no longer holding pressure.

    If it's within warranty, just take it in. Otherwise, I think it's time to have a little fun dropping the tank. :) Recommend you DON'T fill your tank back up until you get it figured out! (worst experiences I have are when people think the failure is "bad gas" and go FILL up the tank and then bring it to me to replace a fuel pump. Nothing like figuring out how to remove 20+ gallons of gas without making a mess and disposing of it if it's contaminated in the process. Modern vehicle's anti-siphon screens in the fuel port might be called "#$%($*&% screens more accurately. Personally, I've had to spill gas multiple times for people who "topped it off" before bringing it in. I hate those...

  5. workman482

    workman482 New Member

    Yeah, don't you know they only fail when the tank is full. Lol. I've had that lovely experience.

    Well, disposed of some used oil at oriellys and checked the fuel pressure. At initial hookup had 0 psi. Turn the key on and had 8 psi. Started truck went to 50 psi, shut it off and immediately went down to 10 psi and dropped go 0 psi within a few seconds. New fuel pump will be here tomorrow.
  6. Skippy

    Skippy Member 2 Years 100 Posts

    If you're doing it yourself, I've found a 3 1/2 ton jack makes a HUGE difference when putting the tank back up. (Getting it down isn't a big deal.. Getting it back up and centered properly is the hard part if you're doing it alone!)

    Also, if you've not done them before, be sure not to use anything that will create a spark when loosening the fuel pump retaining ring. And ALWAYS undo your negative terminal on the battery!

    Sparks are bad news...

  7. workman482

    workman482 New Member

    Thanks for the tips. I'm going to take the bed off to change it. I've talked about it and seen it done so I decided to give it a try. Seems the biggest down side is you need a helping hand to safely remove and reinstall the bed.
  8. Skippy

    Skippy Member 2 Years 100 Posts

    I've never had a problem lowering the fuel pump, btw. It's two brackets holding the thing up. Just drop the rear bracket first, then lower it enough to disconnect the lines, then complete the other bracket, pulling the fuel tank is a piece of cake! holding it up there while sliding the two bracket bars in place is what takes time. With another person, it takes me 45 minutes from start to finish. Alone, it's usually 1.5 to 2 hours (yeah, it's that long to get that thing back up there!).

    If you're going to have someone pull the bed, you might find the dropping tank is just easier.

    My 2 cents...

  9. ASK

    ASK New Member

    Skippy...have you heard of the access panel cut in the floor board method? That seems easy and would allow access for the next time, if there needs to be one. I have seen a video but I don't recall where. It shows measurements as to where the cut needs to be. In my case it would be under the back seat on the Extended cab version. Sounds like a good idea. What do you think?
  10. j cat

    j cat Epic Member 5+ Years 1000 Posts

    with lots of fuel you do not drop the fuel tank. you slide the bed back 1 foot or so and then tilt bed up for access to the pump ring.

    any wiring changes must be soldered wire splices with connectors. also the soldering need be heat shrunk sealed from water.

    you never use any airtex products even if they are free !

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