fuel guage empty to full

I have a 2000 Silverado Z71 with the fuel guage swinging from empty to full and all in between. I have heard of others doing this. I guess maybe its time for a new fuel module. It's been doing this for a couple of years, just keep putting it off. Is it easier to move the bed back or drop the gas tank? Also I have developed hard starting problems here lately, It having too crank extra long before it starts up. Could this be a sign the fuel pump is getting ready to go out. Any info would be greatly appreciated

could be anything.
read codes 1st.
measure fuel pressure next.

this issue is discussed all over the web. some say, dropping tank is OK. many say, it is much easier to scoot truck bed back, to clear the fuel pump and sending unit.
some say, 5 adults can take bed off completely.
some say, it is cleaning a ground wire on sending unit harness that does it.

pick your poison.

I'd say, should you have that truck bed moved, do as much replacements as you can, while you there.

The sending unit is bad and is a common problem on GMs.

I have a 2000 Silverado Z71 with the fuel guage swinging from empty to full and all in between. I have heard of others doing this. I guess maybe its time for a new fuel module. It's been doing this for a couple of years, just keep putting it off. Is it easier to move the bed back or drop the gas tank? Also I have developed hard starting problems here lately, It having too crank extra long before it starts up. Could this be a sign the fuel pump is getting ready to go out. Any info would be greatly appreciated

my guage does this intermittently since 2000...
if you hit the fuel tank bottom and the guage works,, this is simply a coating of film , that the fuel tank pickup has on it interferring with the current flow...

my plan is to live with this until the fuel pump is replaced...
also use of injector cleaner does reduce the problem ...but no cure..

my guage does this intermittently since 2000...
if you hit the fuel tank bottom and the guage works,, this is simply a coating of film , that the fuel tank pickup has on it interferring with the current flow...

my plan is to live with this until the fuel pump is replaced...
also use of injector cleaner does reduce the problem ...but no cure..

He's right. When I worked at the dealer we replaced a ton of fuel level sensors even under warranty for erratic gauges. The were almost always fine, except the fuel varnish or film on the contact strip on fuel sensor. But, they are cheap enough, while there, I would just replace it, I wouldn't chance cleaning it up and putting it back together. If your tank is about empty, drop the tank. If its full, pull the bed. Like said, pulling the bed is not hard at all if you have air tools, and 4 guys can easily set it off. Just put some shop towels at the corners of the bumper between the bed and bumper to protect your paint, and disconnect the filler neck before you get it in the air 1 foot and realise you didn't :) ask how I know.... Same goes for the ground strap between the frame and bed if its got it, if it don't, it is between the fillerneck and frame...

PULL THE BED if you change the pump!! The first four times I changed pumps on GM trucks I layed on the floor fighting with the tank and hoses and fuel line connections,etc.....The last one I decided to pull the bed and had no problems what so ever. It's just eight bolts, filler neck, ground strap and tail light harnesses. Very simple, and, it only takes two guys to move the bed off if it's a shorty. I'll never drop another one of these tanks again....

I agree, lift the bed. When I changed my fuel pump the plan was to use my dad's engine hoist. After we got the bed unbolted, we lifted it up to see how heavy it was and didn't use the engine hoist. It's lighter than we were expecting.

Resurrecting an old thread, I have the same issue with fuel level guage floating around, now stuck on empty with light on. Dealer says that it could be cluster or sending unit.

I'd like to rule out one vs the other myself. Does anyone know of any instructions online on how to check the voltage to the gauge cluster?

TIA

Resurrecting an old thread, I have the same issue with fuel level guage floating around, now stuck on empty with light on. Dealer says that it could be cluster or sending unit.

I'd like to rule out one vs the other myself. Does anyone know of any instructions online on how to check the voltage to the gauge cluster?

TIA

the fuel pump connector has wires to it 2 for the pump motor the other 2 for the sender. the sender resistance is 250 ohms full tank. 40 ohms empty tank. now lets say your sender is open you may think that it will then read over the full mark well the pcm when it sees high resistance more than it knows what it should be will cause the dash gauge to peg below empty. GM installed defective fuel pump assy in these 2000 vehicles .. I still have this issue but after driving a few min the level then is correct .. when I first start it up it always pegs empty. back in 2002 GM tried to charge me $800 to fix this . also these defective pump assy are no longer made/available. the assy has changed so this will require you to cut in a new connector for the new GM pump assy that does work with ALCOHOL FUELS !!!!!