Wacky Fuel Gauge

gasoline
gauges
#1

Ok guys, help me figure this one out. The fuel gauge on my 2000 S10 ZR2 is out of whack. It reads full when I know it isn’t. It will suddenly drop to empty triggering the Low Fuel warning light, then will jump back to full again. Sometimes, I’ll shift from drive to neutral and the gauge will move back and forth eradically. When I go back to Drive the gauge goes back to full (vehicle is sitting still). I checked the fuel pump and it’s producing about 60 psi and doesn’t leak down too fast when shut off. I repaired a faulty ground wire at the tank and the sending unit tests ok for power and ground. Repairing the faulty ground at the tank did not solve the problem. What is the connection between the gear selector and the fuel gauge? Is 60 psi adequate pressure? The truck starts fine. Occasionally when first operated I notice a hesitation in the acceleration. The truck will sputter and act like it wants to backfire, then it will take off and run fine. I have replaced the fuel filter but the old filter didn’t appear to be plugged and the hesitation persists. I have replaced the spark plugs as well. Is the hesitation related to the fuel gauge problem somehow or is it an isolated problem? HELP ME PLEASE OH GREAT AND KNOWLEDGEABLE ONES!

#2

You are combining three issues, a drive ability issue, a apparent electrical system issue, and a inaccurate fuel indicator.

I would deal with these issues one at a time keeping a eye open for some connective condition.

The inaccurate fuel level would be the place I would start (not expecting the repair of the fuel gague system to fix the other two). I would drop the tank (or if you have three friends you can pull the bed) and ohm out the sender, I would replace the pump and sender even if things check OK, the pumps and senders are not very “robust”.

Make sure you get the right pump and sender, install it correctly and then you can remove it from your list of possibilities. Just the way I would go at the problem.

#3

I don’t think the transmission selector has anything to do with the fuel gauge. I had the same problem with the fuel gauge on my 2006 Chevrolet Uplander. It was on warranty and the dealer replaced the sender unit for the fuel gauge. That cleared up the problem. The service writer knew right away what the problem was and the dealer had the sending unit it stock. Apparently, this sending unit has been a problem on some GM vehicles.

#4

My 2000 is not as crazy as yours, yet! Although the fuel gauge has droped a few times…

#5

I Believe You Will Find A Bad “Wiper” On Your Fuel Sender In The Gas Tank

These “wear-out” or disintegrate for some reason. The little thin metal “fingers” on the wiper go away. It’s fairly common.

#6

I Bought A $40 GM “Sub Assembly” Of A Whole Sending Unit And Used Just The Wiper To Replace A Bad One A GM Car.

It works great. A little more labor saves you a bunch of money!

Who knows maybe this “sub assembly” that is designed to clip into the sender, actually fits right into the senders on these trucks. I think GM makes these available to save costs on warranty repairs, like the one mentioned above.