Hello, I haven't posted in a while, but I have a question some of you better genius' might be able to help with.

I have a ecsb z71, 5.3 ltr with approx 119K on the clock. I have allready done the notorious ignition switch problem fix. But now right after I fill up the tank and down to about 3/4's of a tank the fuel gauge sometimes goes to "empty" with the "low fuel" light on. I do one of two things, either shift to neutral/park or two, shake the truck side to side and it comes back to the right amount.

Any ideas on what this could be??? I have heard that it might be the sending unit. I have heard that it is the computer board behind the dash, and I have heard it could just be the gauge cluster board???

Any and all help is greatly appreciated!!!

Thanks in advance also.

 

It's the sending unit. Atleast that is my guess. I've already replaced mine.

 

my wifes truck just started doing the same thing this weekend, GM has a bulletin out about it

<p>Repeat Inaccurate or Erratic Fuel Gauge Operation on 96-05 Passenger Cars and Light Duty Trucks - Runs Out of Gas - contaminated contamination control crank engine empty fill gas inoperative IPC low #PIP3074 - (Jul 21, 2004)
Repeat Inaccurate or Erratic Fuel Gauge Operation on 96-05 Passenger Cars and Light Duty Trucks - Runs Out of Gas

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The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
Condition/Concern:

Some vehicles may run out of fuel while the fuel gauge still indicates that there is fuel in the tank. Due to different reactive sulfur levels in gasoline, this may be noticed more in certain areas of the country than others.
Recommendation/Instructions:

This could be the result of reactive sulfur in the fuel, which can cause corrosive film build up on the fuel level sensor contacts. This film may change the resistance of the fuel level sensor and affect the fuel gauge operation.

If the fuel level sensor has been replaced for this condition, came back after a period of time with the same condition and the published diagnostics leads to fuel level sensor replacement again, the following may prevent a repeat occurrence:
Properly dispose of all fuel in the tank.
Clean the inside of the fuel tank. (See the SI "fuel system cleaning" procedure.)
Replace the fuel level sensor.
Refill the fuel tank with fuel from a high quality, high volume filling station.
Advise the customer to only use fuel from a high quality, high volume filling station.

Note: If the vehicle is equipped with a gasoline engine, refer to bulletin 04-06-04-057 for installing a bottle of GM Fuel Injector Cleaner, part number 12345104, to the fuel system. In addition to cleaning fuel injectors, this may prevent future gas gauge concerns that are due to related to corrosive film build up on the fuel level sensor contacts.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.
Models:

(96 - 05 All Passenger Cars) and (96 - 05 All Light Duty Trucks)

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GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATIOn

 

So basically I have three options...
1. Deal with it and not worry too much about it.
2. Take out the sending unit and CLEAN THE LIVIN CRAP OUT OF IT, put it back in and not worry about it.
3. OR buy a new sending unit and replace the one in the truck?

Thanks for your help guys!!!