This is the second truck that has developed this problem. An 82 full size and now an 87 full size. The gas guage fluctuates as you drive and go over bumps, come to stops and leave from stops. It will fluctuate as much as 1/2 tank. I know there must be a buffer which prevents this that has failed somewhere in the electrical circuit .... but where? I'm thinking it is built into the gas guage but can't find any info. in any of the service manuals. Anyone experience this and found a fix? Thanks, Eric M.