Gas gauge troubles

[xtreme80]

Hey guys,

Last night my gas gauge started giving me troubles. I was cruising, looked down, and it's pegged at full. It actually should have been reading half tank at the time. Then it jumped down to 3/4 tank, and back up, and its just been fluctuating all over since last night.

When the needle moves, it's very shaky and jerky when it moves... but the sending unit is fairly new (8 months).

Would you guys say it's the sending unit and not the gauge, based on the shaky needle?

Thanks everyone

[78 Big10 454]

I had the same exact problem in my 78 shortbed. I got under the truck on the passenger side and traced the gas gauge wire from the tank forward and I found that the wire had the insulation worn away and was grounding against the frame. This was right below the passenger door. Because the wire was not secure, it would move in concert with the truck's movement and fluctuate as it grounded against the frame. Track the gas gauge wiring the full length of your truck to make sure that the wiring is in good shape and securely mounted.

[xtreme80]

Originally Posted by 78 Big10 454

I had the same exact problem in my 78 shortbed. I got under the truck on the passenger side and traced the gas gauge wire from the tank forward and I found that the wire had the insulation worn away and was grounding against the frame. This was right below the passenger door. Because the wire was not secure, it would move in concert with the truck's movement and fluctuate as it grounded against the frame. Track the gas gauge wiring the full length of your truck to make sure that the wiring is in good shape and securely mounted.

I talked to my dad and he thinks it's a wiring issue too. But I also found out that I've got a gauge tester in my toolbox outside (box was given to me when pops stopped working on cars) so I'm going to trace the wire and hook up the gauge tester and see where that gets me. Should be able to eliminate two of the 3.

Thanks for the response buddy

[87Bob]

Something else that has been happening is that many of todays fuels have high concentrations of tarnish builders in the fuel. Starting with the C5 Corvette the sending units have been getting varnish on them and not reading correctly. So if you check it out and cannot find a external reason for bad readings try buying a can of Techron you can get it at the auto parts stores. Or you can run a couple of tanks of Shell gas through it and it may solve the problem. If you think this is BS check this out---- http://forums.corvetteforum.com/show...hlight=thecron there are more postings if you care to do a search.

[COMP]

Originally Posted by 87Bob

Something else that has been happening is that many of todays fuels have high concentrations of tarnish builders in the fuel. Starting with the C5 Corvette the sending units have been getting varnish on them and not reading correctly. So if you check it out and cannot find a external reason for bad readings try buying a can of Techron you can get it at the auto parts stores. Or you can run a couple of tanks of Shell gas through it and it may solve the problem. If you think this is BS check this out---- http://forums.corvetteforum.com/show...hlight=thecron there are more postings if you care to do a search.

have seen it help

[xtreme80]

Cool I'll keep that in mind as well. I've heard about it but I usually only use Chevron gas and you know their saying...