GM Fuel Treatment Plus

[baby141]

I have an erratic fuel gauge. I have to reset odometer at every gas fill up to keep track of mileage. Quoted $600 to replace the unit but I tried the GM Fuel treatment Plus in the gas tank first. Anyone have luck with the treatment resolving the problem?

[gmtech1]

That must be some pretty special treatment to repair a fuel sending unit!

[sverker]

The fuel level sensor is a variable resistor with a floater on an arm. The part cost $120 from rockauto, or you can replace the whole fuel pump assembly which is a $200-$300 part depending on brand. The fuel tank needs to be taken down but apart from that it shouldn't be very complicated job.

I've also heard there is an electrical connector in the floor behind the driver seat which if it corrode will amoung other things cause the fuel gauge to behave erratic so you should probably check that first (not sure about the location though)

[Tech II]

Sverker is correct about the harness connectors in the floor, driver's side, approx behind driver's seat....just take apart and look for "green" corrosion....if ok, then disconnect harness going into tank.....turn key on....should read full...get a 140 ohm resistor.....attach it to the harness connector for the fuel level circuit....if it reads half full, you need a sender....

[JabbaTHutt]

Ya as others said check the plugs under the van behind the drivers seat.

A few years ago, we went into the local hospital in a driving rain storm to see the wifes mom. Power slider on drivers side decided to open back up and I saw it close. We was inside for 30 minutes to 60 minutes and came out to a wide open door and water everywhere behind the drivers seat. Van started but the fuel gauge was crazy. Went to the mechanic and he pulled the plugs under there and they just dripped water everywhere. Blew them out and dried the best we could and it was fine, went back to normal. Did find some green in there too so it had been wet before. I tired some contact cleaner and stuff on the connectors and it seemed fine, then one day it wouldn't start. Hmmm no fuel pump sounds, got under and pulled the one I knew went to the pump and sure enough more green so plugged and unplugged it a few times and all was fine. clean it all again. Now I am like months and months later I am 6 or 7 hours from home in a city where I know no one and it does it again. Daughter is freaking as she has just moved there for school. Well I know what it should be and sure enough I do the same thing and it fires right up. Get back home and clean it again but now the contacts are mostly just the steel. I then remember someone giving me so HIGH voltage HIGH current protection spray. So I spray all the plugs under there. I did also get some dielectric grease but so far its been 3 years and hasn't happened again, so I never did use the grease.