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Discussion Starter #1
With my GMC at 55k miles when the fuel starts reading around a ¼ tank or so the gas gage intermittently will jump up to, or past the full mark. Or it will go to ½ tank or ¾ or anywhere in between.

So I ran out of gas yesterday, but the gage showed between ¼ and ½. You could hear the fuel pump starting to suck dry. I coasted into a gas station imagine my luck. Once I started filling up, 1 gallon then 2 gallons, the gage jumped to full then hung around there then dropped to empty then back to ¼ then stabilized once it was above ¼.

I wonder if there is a dead spot in the sending unit. Any ideas. I can easily pull the tank.

Thanks

Pie Boy
 

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Discussion Starter #2
99 (old body style), full size regular cab, 3/4 ton, 4x4 towing package, 8700GVW, SLE. Thanks
 

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Thanks LM for the concise info I believe my vin is an "R" code. Either way, being that it seams you’re familiar with this, what is the typical failure mode of the sending unit for the symptoms I have describe? Is it electrical, mechanical a combination? Thanks again for your input.
 

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Discussion Starter #4
Thought I'd give you some background on what I found.

Pulled the tank Sunday night. Pulled the sending unit/pump.
Discovered that there are two small stainless spring-steel arms, each with three tabs on them. This part of the float mechanism

Each of the three contact tabs sweeps across two sets of ribbed pick-up leads, which are on a small circuit board. Each of the tabs had what can only be described as burrs as if the stainless had worn or they have picked up material off of the pick-up leads. I believe the tabs were worn

Well anyway holding this assembly in an in car position and loading the float as if is was suspended near what would be a near empty state, the pivot mechanism has started to develop enough play, along with the worn stainless tabs, that a gap would occur between the stainless float tabs and the pick-up leads. This gave the false reading.

For what it was worth, my time an hour and twenty minutes, I adjusted the stainless float tabs to take up the amount of “slop” that had developed in the pivot mechanism and add an extra 1 degree to the adjustment so there is enough preload to make up for future wear.

I checked the ohm spec and wala works like a charm. So far so good after 200+ miles The dealership wanted an outrageous price for parts and labor.
 

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314boi said:
So far so good after 200+ miles The dealership wanted an outrageous price for parts and labor.
You can find a way to rig most repairs done, good job for saving yourself some money. From a dealers perspective, in order to guaranty a repair we have to fix it the right way, which would be to replace the part. No matter how well you cover your rear, if you charge a customer for rigging something, they will expect you to do it for free the next time it breaks, not to mention the liabilty involved if our engineering causes a fire or other safety hazard. I am sure your fix will work, but for how long?
 

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ace70568 said:
What did you use to bend the tab's cause there kinda fragile?
Also how did you bend them?
I think it must have worked, as it was fixed almost THREE years ago...
 

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GMCSonoma said:
I think it must have worked, as it was fixed almost THREE years ago...
DOHHHHHHHH!!!!! :eek: :eek: :eek: I just assumed it was a new post. Of course he could have blown up and been to embarrassed to tell us his quick fix didnt work. :D
 
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