Another Fuel Pump Change

VinceJE · June 18, 2010

I think it's time to change the fuel pump assembly in my 2002 Sierra 1500. I've got the hard start / bad check valve issue so many folks have experienced. I'm gonna do the bed-lift method.

My question is... Are any special tools needed to detach the fuel lines from the pump? (Does it have the quick disconnect fittings?)

Also... I once saw a great illustrated write-up on lifting the bed & changing the fuel pump. I can't seem to find it now that I need it. Does anyone know the link to it?

txab · June 18, 2010

I think it's time to change the fuel pump assembly in my 2002 Sierra 1500. I've got the hard start / bad check valve issue so many folks have experienced. I'm gonna do the bed-lift method.

My question is... Are any special tools needed to detach the fuel lines from the pump? (Does it have the quick disconnect fittings?)

Also... I once saw a great illustrated write-up on lifting the bed & changing the fuel pump. I can't seem to find it now that I need it. Does anyone know the link to it?

Here's one thread:

http://www.gm-trucks.com/forums/index.php?...c=83727&hl=

nickvrebel · June 18, 2010

easiest way to disconnect the fuel lines is to get a fuel line/ a/c line disconnect tool from the auto parts store.

no other special tools are needed. a screw driver with a hammer will knock the retaining ring loose. Removing the bed is the easiest method by far. Remove the tailgate, unplug the light harness (behind the license plate), couple bolts at the fuel filler door and I think it was 6 or 8 bolts that hold the bed on. Hardest part is finding 3-4 friends to assist with picking it up, case of beer usually helps with that issue. I always just set the bed in the grass on the side of the driveway while I was working.

VinceJE · June 18, 2010

One more question... The article (thanks for the link) mentions that you have to "re-learn" the fuel gauge because of the new sending unit. I assume this to mean the gauge has to recalibrate itself. ?? Is there a process for that or is it just one of those deals where it re-learns by itself over time?

southern comfrt · June 19, 2010

yes it is a simple job ,you can buy the tool for the fuel lines at sears but i just manipulated it with a very small screw driver.in my case the wiring harness that is on the fuel pump itself is what went out,you should be able to purchase this seperate if thats your problem,it could be just a burnt connector

VinceJE · June 19, 2010

Thanks for the tips.

The pump still runs but the pressure leaks down to 0 within a few seconds after turning the key off. 120k on the clock. Hard to start but runs great once started.

bossier62guy · June 20, 2010

Thanks for the tips.

The pump still runs but the pressure leaks down to 0 within a few seconds after turning the key off. 120k on the clock. Hard to start but runs great once started.

Don't forget to install a new fuel filter while you're replacing the pump.

jblakeney · June 20, 2010

Yea, bed off is the only way. Dropping the tank is for the birds. Then again, I do have a 2post lift to do the lifting.

Jbo

johnnyquick · June 20, 2010

I did mine recently with the dropping tank method and it was simple simon with a few bolts, and a floor jack, I disagree with the anyone using a screwdriver and a hammer to dislodge the old pump, use a block of wood or a PLASTIC splitting wedge instead, the tank is FULL of fumes and a spark may make you news worthy.

Please do yourself a favor and use a Delco/ Delphi pump instead of an off brand, I did and had to replace it with a good one in only 2 years.

Maybe next time I will try the bed removal method but dropping the tank was indeed not an issue if you go that route.

Cheers

KMGZ400 · June 20, 2010

I think it's time to change the fuel pump assembly in my 2002 Sierra 1500. I've got the hard start / bad check valve issue so many folks have experienced. I'm gonna do the bed-lift method.

My question is... Are any special tools needed to detach the fuel lines from the pump? (Does it have the quick disconnect fittings?)

Also... I once saw a great illustrated write-up on lifting the bed & changing the fuel pump. I can't seem to find it now that I need it. Does anyone know the link to it?

wait, what do you mean hard to start? i have been expirencing the same thing and have been trying to figure out what it it.

txab · June 21, 2010

I think it's time to change the fuel pump assembly in my 2002 Sierra 1500. I've got the hard start / bad check valve issue so many folks have experienced. I'm gonna do the bed-lift method.

My question is... Are any special tools needed to detach the fuel lines from the pump? (Does it have the quick disconnect fittings?)

Also... I once saw a great illustrated write-up on lifting the bed & changing the fuel pump. I can't seem to find it now that I need it. Does anyone know the link to it?

wait, what do you mean hard to start? i have been expirencing the same thing and have been trying to figure out what it it.

Have you checked your fuel pressure?

VinceJE · June 21, 2010

The hard start problem has been going on for a couple years and is getting progressively worse for me...

Many times it will not start after sitting for a half hour or longer. Have to crank it 2 or 3 times & then it will stumble sometimes for a second before smoothing out & running good. It runs great once it's started. It will restart on the 1st crank if done immediately after shutting down.

I did alot of research and found that this is a somewhat common problem caused by a check-valve in the pump that is failing to seal & hold the pressure (and more importantly fuel) on the engine. The fuel drains back towards the tank due to gravity. It starts somewhat more consistently if you turn the key on (not start) for a few seconds (you will hear the pump running, then off, then back on again for a couple seconds before cranking. I suppose this is re-pressurizing & pushing the fuel back to the engine.

I checked the regulator (per several posts on this site w/ how-to's) & it seems fine. I bought a fuel pressure test gauge and found that the pump maintains 51psi while it's running, but the pressure bleeds down to zero within a few seconds of shutting it off (leak-down). I think I read somewhere that it could also be a leaking injector, but I think that's rare and I would think that it would not be running perfectly otherwise.

Others can chime in, but I believe the most likely cause of this is the check-valve which I understand to be a part of the pump assembly itself. Mine has about 120k on it and I figure that's about the longest average life span from what I hear.

A few other things that I've learned about doing this job...

1- Most aftermarket parts houses (Oreilly, AZ, AAP, etc) do not carry a replacement pump assembly.

2- Only replace with AC/Delco pump assembly. The savings from the aftermarket brands often ends up costing you more time to replace again when it fails prematurely. (not to mention there is never a convenient time or place for it to fail).

3- The pump is not cheap. My local GM dealer wanted $460 for it at first and then came down to $380 when I told them that that was ridiculous. The best deal on an AC/Delco (OEM) pump that I found was at XL Parts for $301. They are a major supplier of OEM parts to the dealers in my area and have convenient store fronts all over the Houston area. I think they also have locations in the DFW & OKC areas too. They are always the cheapest place to get OEM parts. Many times they have OEM parts cheaper than the aftermarket brands.

4- Lifting the bed to get to the pump is the easier than dropping the tank for most people.

5- Plan to change the "truck-side" if the fuel pump wire harness connector. Many folks have claim the connector on the truck that snaps onto the pump is weak & causes a low voltage situation at the pump which will cause it to fail prematurely or will lose contact altogether causing the pump not to have electrical power at all. The connector is even provided with the pump in some cases and it's a common replacement part you can purchase separately if it's not provided with yours.

6 - You need a set of fuel line quick-disconnect tools to detach the fuel lines from the pump. I'm not sure what size is required, but you can pickup a small set at the parts store or Harbor Freight for just a few bucks.

7- This is not a complicated job if you know how to turn a wrench and have a few extra hands to help you move the bed. Doing it yourself will save you big$$$ on labor. Every shop I called to do it for me wants at least $400 just for labor. They all want to charge for pulling the tank because "that's what the book says you have to do". (BS!!)

Sorry for the long post, but I wanted to try to share all my points for others that may have a similar issue.

jblakeney · June 22, 2010

Vince,

I have been in the aftermarket for around 10 years. Spinning wrenches I don't want to count. People tend to over look the aftermarket. AirTex, Bosch, Carter, and Delphi ALL have drop in units for the GMT-800's....... But do not forget NAPA HAS DELPHI (which is GM).

My pump made and odd noise cranking one Sunday night the next Saturday I replaced it.... It was not making more noise than normal and was not much quieter than the new one I put in. I had 160+k nearing 170k....

Okay here goes.

2002 GMT-800 truck 5.3

Flex Fuel (VIN Z)

Delphi -- FG0466

Airtex -- E3572M

Bosch -- N67452

Non-Flex Fuel (VIN T)

Delphi -- FG0053 -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Delphi -- FG0271 -- 1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

Airtex -- E3500M -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Airtex -- E3501M -- 1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

Bosch -- N67305 -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Bosch -- N67429 --1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

-------------------------------------

2002 GMT-800 truck 4.8

Delphi -- FG0053 -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Delphi -- FG0271 -- 1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

Airtex -- E3500M -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Airtex -- E3501M -- 1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

Bosch -- N67305 -- 2 electrical connectors on the top (EVAP Emissions) -- Also Stamped TCF

Bosch -- N67429 --1 electrical connectors on the top (NON-EVAP Emissions) -- Also Stamped TCU

OK, just my good measure. I have heard many people say just don't run the pump dry. Keep it submersed in fuel (at least a 1/2 tank). Change the fuel filter every year (if you have one).

When changing a fuel pump, replace the fuel filter, fuel pump relay, and fuel pump fuse.

Delphi is the same as what is in the AC Delco box and the Genuine GM Box.

Jbo

Edit:

1st picture - FG0053

2nd picture - FG0271

3rd picture - E3500M

4th picture - E3501M

jt8399 · June 22, 2010

Vince, I literally replaced my fuel pump his past Saturday. It was the first time I ever done it. I didn't have a clue where to start. The Chevy Dealerships quoted me a $1000 for the job, so it was a no brainer for me to do it myself. By the way...TXAB, you're a bad ass. One of the links you posted(the same you provided Vince) with the pics and directions from two different people is all I needed. The only reason why I joined this forum was to be able to view those pictures. Now I'm a member of a very informative site. Vince, I'm sure you know this, but just follow those instructions in that link. Heres my quick summary.

1. Disconnect your baterry. (to disable your fuel pump)

2. Remove your fuel pump fuse. (I forgot to do this, but silverado manual at autozone and other forums said to do this.)

3. Remove gas cap (relieve pressure)

4. You may or may not have to do this, but I did. Remove fuel filter and replace with new one.

5. Remove 3 screws from filler neck.

6. Remove 8 bolts from underneath the bed.

7. There's 4 electrical connecters behind your license plate. Disconnect the two that are vertical. (one on top of the other)(or all of them if thats confusing)

8. Remove your tailgate.(less weight)

9. Stuff towel, shirt, or whatever between passenger side rear bumper and truck bed. (If you don't, the weight from the bed on the bumper will do some damage. That's the point that will keep the bed from sliding off.)

10. You can go at your truck bed 3 different ways. 1. Have some manpower to lift and move off to the side.(best b/c it gives you wide open space to work, no biggie though) 2. Use a floor jack to lift it up and secure it with 2 jack stands.(you can do this by yourself) 3. If you don't have a floor jack or don't feel like using one, you will need another person for this. This is the route I took. I didn't have the manpower and didn't want to invest in a floor jack after paying for the fuel pump). My girlfriend helped me on this one. Get underneath the wheel well and lift up the bed while your helper puts at least one jack stand underneath the bed to secure it. Lift up again to put the second jack stand underneath. Lift again and raise both jack stands so you can have plenty of room. Once secure, shake the bed pretty good took make sure its sturdy.

11. Disconnect electrical connectors from fuel pump.

12. Use a hammer and a flat head screw driver(or whatever you got) and hit the ring counter clockwise to unlock.

13. Once unlocked, use vacuum and/or air to remove as much dirt as you can. Try your best not to let any dirt fall in the tank. If some does, just plan on replacing your fuel filter again shortly. (That's my thought on it.)

14. Disconnect Fuel lines from pump. Tis was the most time consuming part for me. You will need some disconnect tools. I used the cheap ones oreillly's. Brand was Lisle. Black plastic. Fittings for medium and large fuel lines. I used screw drivers for the small fuel line. Be careful not to break fuel line connectors. Don't freak out if you break some plastic off the old fuel pump if you have use some force, but don't break the fuel line connectors.

15. Re-vacuum and/or spray with air to remove dirt. Then pull out the fuel pump. Depending on how low the truck bed is (If it's on jack stands, you may have raise it a little higher or pull out the pump at an angle. Whatever you have to do. (leave old fuel pump standing, fuel will go everywhere if on side)

16. New fuel pump will probably have a new harness. Mine did. You will have to cut old harness and crimp new one. Directions and supplies included(not crimpers)( Airtex 2 connector w/ EVAP - 271.99 Oreilly's)

17. Just refer to old fuel pump to make sure your good to go. (Rubber Seal, Lock ring, float). Install new pump. line in up just like the old one. It will seem to tall at first. When positioned right, pushed down with some force. Rubber ring will catch and keep it in place.

18. Tighten lock ring. You'll now where to hit it to tighten it. This too a while for me, until I did this. Hit the notches in order. (clockwise obviously). 3 or four time then on to the next. Keep doing this in a circle. Even if it seems like it's not moving. It eventually will. Hit until there's no more room to move.

19. Connect Fuel Lines and electrical connectors (quick and easy)

20. Hook up battery, fuse, and fuel filter if still off and start it. Mine started but was running like crap for a minute or so. I then turned it off and for a few seconds and re started it and it ran like a champ. Maybe there was air in the lines. I don't know. Let it run for a while, then put your bed on. Reconnect connectors behind license plate and tighten gas filler and you're good to go!

Note: Be careful not to bump in to Bed if your working underneath. I had a little scare. Good luck!

P.S. - If missed something, my bad. I typed this up pretty fast. I wish I would have taken pics, but all the pics you need are in the links provided by TXAB.