Suburban fuel pump replacement

mcgyvermcgyver Member Posts: 13
My noisy fuel pump finally quit and blows the ECM fuse when turning on the ignition switch which tells me the fuel pump relay is shorted out. So I need to change the pump and relay but my 1999 unit is almost 10 years old and has 30G of gas in the tank. There is no way to drain it (250 lbs) which will slosh around while dropping it so I want to replace it in the truck.
Why didn't GM put a removeable panel under the carpet to access the pump from above? And you think this one is hard, the later Camaros and Firebirds have to drop the rear axle to drop the tank!!
My plan is to cut the floor and replace from above,
then replace with a galvanized metal sheet, sealed and popriveted in place.
Anyone else out there done this??
Any comments or suggestions??


  • kiawahkiawah Member Posts: 3,666
    I'd just drain the tank. Put a thin tube (siphon hose) past the gas filler slosh flapper, and down into the tank. I did it all the time to fill up fuel for the tractor on my 96, which had a 42 gal tank. I usually fill up the tractor and four 5 gallon gas's much easier than hauling all of those thiings to the gas station.

    Seems like you are making an awful lot of work for yourself to cut out the floor.
  • mcgyvermcgyver Member Posts: 13
    I was told my '99 K2500 has a rollover valve down where the filler neck attaches to the tank so not able to siphon any fuel out. And by having an access to the top of the tank permits an emergency pump replacement on the road easier.
    The older noisy pump died shortly after installing a Whipple supercharger on the GMC to help tow my 7k trailer easier....492 torque. The pump couldn't handle the added boost needed.
  • kennyb79kennyb79 Member Posts: 1
    My Dad used to do this any time he needed to replace a fuel pump on any vehicle. fuel pump gone, get out the air chisel. That was his reasoning tom once they go they'll go againa nd thats the only way you'll ever be able to chenge them on the road. On a pickup its easy you still have the bedliner to over up the patch job so it doesn't look bad. I'm thinking of doing the same thing to my suburban, the pump just let go. another good reason, if you ever have to change the fuel lines you have access to the top of the tank. By now your already done with the did iit work out?
  • karr2069karr2069 Member Posts: 1
    that's a bad design . oh I also had to change a fuel pump in a camaro last week. I'm an Auto tech. so I feel your pain . You can use a small hose to siphon tank difficult to get in tank sometimes but 3/8 inch or smaller will usually work . good luck .
  • shyneposhynepo Member Posts: 2
  • arriearrie Member Posts: 312

    When you checked for fuel coming out of fuel line was your engine running or not? I guess not as the pump quit?

    When you turn the key ON the pump comes on only for a couple of seconds if you do not start the engine. Fuel pump will not run constantly with key in ON position if the engine is not running.

    When you check for fuel being present in the fuel rail it should even when the pump is not running because the pump charges the line during the brief moment it runs. If you do not have any fuel pressure in the fuel line after you just turn the key ON it simply means that either your pump is not working at all or fuel regulator does not hold pressure.

    After replacing fuel pump numerous times I would not think the pump is the problem (even Mr. Murphy would get tired of this) so it leaves you the fuel pressure regulator to check. If the regulator is bad it does not matter how many pumps you replace. It will not work until you fix the regulator issue.

    There is a chance that you really "destroyed" several fuel pumps during the process you have gone thru. This could be possible if there is no fuel back pressure in the fuel line due to pressure regulator problems. This could let your fuel pump to operate on much higher rpm that it is designed for. This may be a far fetch but could be possible.

    Step 1 for you is to replace the fuel pressure regulator and then the pump again if needed. Of course you need to check/change the fuel filter too but they seldom fail in a way that no fuel get thru them at all.

  • burban3burban3 Member Posts: 1
    i have a 1999 i just did the fuel pump on and it still doesnt run. I shut the truck off at the store and it wouldnt start when i returned to it after about 4 min. Truck cranks but wont fire and has spark. At first i thought it was pump, due to lack of pressure and no noise coming from pump. I replaced it to no avail. It sputtered and tried to start at first after the new pump and had pressure and also the pump was priming but it just wouldnt catch. Plugs are wet with gas so i think i may have flooded it trying to get it started. Any suggestions???? 1999 suburban k1500 4wd, 5.7 350 vortec. automatic. Any info would be great...hope its not computer..
  • arriearrie Member Posts: 312

    Your engine is designed to run if 4 basic thing take place.

    1. Your engine gets air.

    2. Your engine gets fuel (at correct spray pressure)

    3. The spark plugs have good spark.

    4. Spark plug firing is timed correctly.

    1. Your engine carburetor probably has an idle air valve. Idle air valve is used to control your engine's speed when you take your foot off of the accelerator pedal. With foot off of the pedal the air intake butterfly valve of the carburetor closes and air that engine needs for running idle enters engine thru this idle air valve that the computer controls for correct idle speed. This is also the route for air when you are starting the car, i.e. when your foot is off of the accelerator.

    Problems with idle air valve should show up also with engine cutting off when you are driving and come to a stop with foot off of the acc pedal but it also could be that the valve is failing so that when engine runs it can pull enough air thru the valve but when you are starting it is not getting enough air.

    To check for this is simply to open the throttle valve by pressing slightly on the accelerator pedal when starting. If it starts then the problem most likely is with the idle air valve.

    2. You mention that your spark plugs get wet with gasoline so definitely engine gets fuel. The question is if it comes in at correct spray pattern, i.e. if fuel pressure is too low or injectors are too worn out (seldom happens) fuel spray might not atomize to fine enough mist for it to mix correctly with air to fire up.

    There is a fuel pressure check point in the fuel rail. You need a special fuel pressure gauge to check it. Just to rule out fuel pressure regulator as a problem I would change it. Part probably cost about $20.

    3. You mention that spark plugs have spark but is it timed correctly? I don't know a '99 engine spark timing. I think it still use distributor? If so, it has a vacuum or electronically controlled timing adjustor which retards spark timing when starting the engine. Make sure this moving part inside distributor freely returns to spark retarded position, i.e. if spark is too much advanced for starting the engine it would have problems starting up.

    Also, even when you see a spark make sure spark is strong enough, i.e. it is a good blue colored spark. Sometimes spark is present but not "hot" enough for firing up the engine.

    If your spark is too weak check that the ignition coil is not bad, i.e. it does not have a leak in ground etc. Ignition coil should not cost much at all to replace ($60 or so) so this is something that could be done just to rule it out.

    Another low cost easy "rule it out" is to change distributor rotor and cap.

  • mcgyvermcgyver Member Posts: 13
    Doesn't matter if a 1997 or a 1999, it is still a FI Vortec motor so there is no carburetor and the ignition advance is controlled by the computer or ECU.

    Arrie is correct, change the cap and rotor and check when the last time the fuel filter was changed. The fuel pressure can be checked at the port on the line using one side of a AC gauge set (R12or R22) and should be around 52psi.

    Good luck....
  • arriearrie Member Posts: 312
    But it still has an idle air valve that by-passes the big butterfly throttle?

    I don't think a '99 is a "fly-by-wire" yet, or is it?

  • breadybready Member Posts: 1
    :( I replaced my fuel pump in my 1999 GMC Suburban about 2 years ago.
    I purchased the replacement at a local parts store. last weekend while traveling home from visiting family are truck broke down on the highway.
    are mechanic says its the fuel pump. i told him it was already replaced not too long ago and that it had a life time warranty. he said that they do not use the Carter brand because they don't last in GM trucks. I aslo talked with a different parts store and they told me the same thing, they do not recommend Carter fuel pumps for GM trucks!!
    has anyone experienced the same thing??
    does anyone know of this??
  • barron2barron2 Member Posts: 1
    Yes I can confirm that Carter brand fuel pumps are crap. I have a 94 S10 Blazer and a 97 Suburban. Both trucks had their fuel pumps go out within months of each other. I put Carters in both trucks and within 4 months had to replace them, 4 months later the carters went out. I put A/C Delco pumps in both and 2 years the Suburban pump is out and the Blazer is still going.

    The Carter pumps are loud, the A/C Delco are quite. I wish I could get a pump that would last as long as the orginal pumps did.
  • shovel52shovel52 Member Posts: 1
    I just purchased this van from a tow company and got a steal on it. The motor runs if fuel is sprayed into the air system but then dies. Is there an easy way to check the fuel pump? I need to check voltage. I live on a busy street and would not be able to hear anything so I need some kind of visual method. I have it on blocks need to get the gas out. Where is the fuel pump located and can you get to it? Can you get to the wires to check voltage? and if voltage how hard is it to drop the tank? I would be willing to cut a hole if necessary. I do have the mechanical skills to do the job but I am not familiar with location etc. Any experience here would be appreciated.
  • reggelsenreggelsen Member Posts: 1
    I have done mine twice (250000km) then when it acted up the third time I started to investigate other issues; there were a recall on the fuel pump module electrical harness, apparently some wires were prone to shave through and cause a ground. I got suspicious after my tank gauge started to act up. I had the recall completed at the dealer (no charge) and now my tank gauge and FUEL PUMP works just fine.
    I have a 2000 Chev Suburban 1500 2wd.
    Just a thought.
  • martiinpanamamartiinpanama Member Posts: 2
    We had the same problem, replaced the fuel pump by taking it down to the ground, draining it, and then reinstalling it, only to have the same fuel pump failure a year later. This time we cut a hole in the floor, took out the pump and then replaced the cut out bit with metal border soldered on and a hinge so it works like a lid. Stupid design. I love the Suburban but now that it is starting to break down a bit (also a 10 year old model) there are many things I would design differently!)

    By the way, I was advised to keep the fuel tank at least a quarter full so that the fuel pump does not have to work so hard and apparently this way will last longer.
  • rockman59rockman59 Member Posts: 250
    By the way, I was advised to keep the fuel tank at least a quarter full so that the fuel pump does not have to work so hard and apparently this way will last longer
    A friend of mine who has a fleet of GM work vehicles was told by a GM rep to keep the gas tanks at least 1/4, better yet at 1/2. Seems it helps to keep the pump from heating up which is a major cause of pump failure.
  • ltlrikiltlriki Member Posts: 1
    I have a 1999 Chevy (C2500) V-8 454 Suburban with 142K miles and I replaced the fuel pumps (AC Delco) twice and now the pump is going out once again but I will not replace it with the same AC Delco junk. Can anyone tell me of the following brands, which fuel pump would last the longest? Delphi, Airtex, Bosch or Carter. I just read a string that stated Carter was not a good pump so I can eliminate that one.
  • mcgyvermcgyver Member Posts: 13
    Sorry to hear of your repeating problem with fuel pumps. Mine was noisy for quite some time before replacing but saved money by buying just the pump and NOT the whole assembly. This cuts the price almost in half but the installation labor at a shop is high..not a quick easy job. It depends on how much fuel is in the tank which can't be siphoned out before dropping it. That's why I cut a hole in the floor and replaced it from above and screwed a sealed plate over the hole. This way future pumps are so easy to access and a DIY job.
    I'd go with the Bosch pump if it were mine to do again. Also check the regulator or kinks in the line causing extra work on the pump that may cause premature failures. The running pressure is normally around 52psi at the check port.
    Good Luck....
  • cfont711cfont711 Member Posts: 2
    edited June 2014
    I need weather stripping and body molding for a 1971 Chevy conversion sportsvan...does anybody have any ideas where to find it - Chevy truck sites are no help...anybody parting one of these out?
  • tep82flhtep82flh Member Posts: 1
    "That's why I cut a hole in the floor and replaced it from above and screwed a sealed plate over the hole."

    was this in a Suburban? if so can you give me an idea where the hole is cut? thanks
  • mcgyvermcgyver Member Posts: 13
    Sorry but I can't recall the exact dimensions and have sold the '99 and bought a newer 2003 model. Maybe someone else will chime in and have the dimensions to share with you......maybe when they drop their tank for a pump replacement.
  • ltlriki64ltlriki64 Member Posts: 2
    Update 99 Suburban (142K miles) V-8, 7.4 liter, 454 fuel pump failures: I installed the Airtex brand fuel pump as my previous (2) AC Delco pumps failed. Both AC Delco pumps were noisy but this new Airtex pump barely hums on an empty tank! I will keep you updated on the longevity of this pump. Also when I purchased the pump it came with the updated wiring harness and wiring diagram so it was a snap to install and I saved $800 by doing it myself minus the cost of the pump and fuel filter. Now if I can only figure out why the needle on my fuel gauge vibrates constantly...New pump had fuel sending unit so I can eliminate that as a problem, any ideas?
  • samsam4samsam4 Member Posts: 1
    Im in the process of replacing my fuel pump for the second time within 6 months but when we install you can hear it turn off then it stops checked the relay fuse can anyone help me please
  • mcgyvermcgyver Member Posts: 13
    Check to be sure you have a good ground, especially if you're up in the snow belt
    which causes lots of havoc with electrical systems. Then check all your plug connections for a firm positive feel. When there is no operation, check the hot side of the fuel pump relay for voltage going to the pump. If there is none there you may have a bad ECU which sends a signal to send voltage to the pump.
    Good luck.....
  • notechnotech Member Posts: 1
    mcgyver, ia ECU differnt from a ECM? I am having some difficulties with a new pump and read about a bad ECM. I have a few things to look at tonight before I post my issues. Thanks!

  • zr1georgezr1george Member Posts: 3
    I need to replace my fuel pump and don't want to buy the Autozone $250 complete pump set up for my 2002 Suburban. Does anyone know of the brand and part number to buy just the pump? I have the numbers for the two pumps in my 91 ZR1 at Autozone and I guess one could buy just the pump for the Suburban. Thanks
  • zr1georgezr1george Member Posts: 3
    Did you replace just the pump and not the whole assembly? If so, where did you get the pump and what is the brand and part number? I have a 2002 suburban.

    Many thanks
  • eman916eman916 Member Posts: 2
    edited October 2011
    I recently had the fuel pump replaced in my '02 Tahoe - 5.3, (not a cheap fix), and 3 hours after I got it back it the "Service Engine" light came back on. I also noticed that the fuel mileage had gone way down, I was around 16-18 mpg, but now am getting less than 10 mpg.

    Took it back to the shop that replaced the pump and they checked the error code, which was a 420 code - Catalytic Efficiency incorrect.

    I am now told that I need to replace the driver side catalytic converter.

    Seems to me that we are fixing the problem, but not addressing the cause. If the engine is runnig too rich, it would cause the catalytic converter / 02 sensors to be reading a bad catalytic converter. They can't tell me what caused the mileage to go from 16 to less than 10.

    Has anyone run into this problem? Talked to the dealer and they thought there could be a couple of injectors stuck open. I am also reading online that one sign of a fuel pressure regulator being bad is dramatic drop in fuel mileage.

    The old fuel pump was only putting out about 25 lbs in pressure, and I'm wondering if that could have caused the fuel pressure regulator to go bad.

    Any ideas before I let the repair shop go on a fishing expedition?

  • cowboy92cowboy92 Member Posts: 1
    I bought one on ebay for 21.99 item number 200642455435. Drives good with no probelms. For anybody looking for this fuel pumps. THEY Are all the same from the inside. OF COURSE DEPEND ON THE YEARS. This is the way to do it, If you see a pump with a listing name like a yukon tahoe gmc and so on. Go in a web sight like autozone. Put in your car information then the same information as the listing you will see there the same part. This is a 3hr job even for a rookie like myself. GOOD LUCK
  • zr1georgezr1george Member Posts: 3

    Thanks for the update. I had to replace the pump in August and had to buy it at Autozone $300+ as it was the flex fuel pump. My Suburban is not flex, however, that is the pump it uses.

    I will check on Amazon and see how much less it would have been. I know I will need a new one in 100K miles!!

    Thanks again

  • carol00carol00 Member Posts: 2
    Is the replacement similar to the 1999 Suburban or the 2003 Suburban. 230 K miles and never replaced the fuel pump. Please help
  • 50panel50panel Member Posts: 1

    I have owned 2 suburbans and in both of them I cut an access hole through the floor right over the pump replacement location and replaced the fuel pumps ...Simple job with an access hole !! Why do you suppose GM didn't come up with the ideah ???

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