i have a 96 ranger with a 2.3l engine and a 5 spd manual 2wd tranny. when the truck is sitting there with the key on it has one reading but when it starts it changes, which do i believe.

 

me, i would the lowest reading,,,,

 

I never trusted the gauge in my 93, I knew I could get 330 miles to the tank, so just resat the mileage and refilled at 290-300.

 

My Ranger & Taurus fuel gauges are accurate, After turning the key on, with the vehicle on Level ground & waiting a bit if they were just moved off a slope. The Ranger slosh module doing its job makes the gauge a little slow to respond after its level, but after it settles down its accurate.


EDIT: If you think yours isn't very accurate, try a 20 oz dose of Techron Concentrate Plus in the tank at the pump before filling, so to get good mixing, with a fuel that already has some PEA in it, like Chevron, Texaco, Caltex, Shell & that'll raise the PEA treat rate 10X above that of the pump gas alone & will often yield results in one treated tank. If we'll regularly use a Top Tier fuel that says it has PEA in it, Chevron says it'll keep the fuel sender corrosion caused by high sulfur fuel cleaned up & the fuel level sensor as accurate as it was designed to be. It'll also tidy up the fuel injectors, intake valves, combustion chamber & piston crowns, so we can get multiple bangs for our bucks spent!!!!

 

I would suggest that the varying voltage from battery charge level to the output voltage of the alternator[when running] make the gauge read differently. FoMoCo put a voltage regulator on the back side of the instrument cluster to minimize the effect of varying voltage on gauge readings. It was a little rectangular box with ground, B+ and output that fed the temp and gas gauges, maybe the amp & oil pressure too, depending.
It chopped the battery voltage by 'vibrating', to limit the effective voltage to somewhere in the 7v range. When the generator or alternator began producing, this thing kept the voltage change within tolerable limits.
I have no idea if there is a similar device, but the B+ voltage produced is different with the engine running or not, so the gauges must be voltage indifferent, or fed conditioned volts to have the same readings.
tom

 

Tomw has it right voltage fluctuations. The only truly accurate gas gauge I ever had was on a 1973 ford F100. When the needle touched E you had better be setting at the gas pump or you where going to walk.

 

thats what i thought,i think i will try a half can of seafoam in the tank before fillup and just go with worse case cinerio (sp) the truck sat for about 5 yrs i have since changed the oil twice and gone through 2 dozen tanks of gas back when it cost 80 bucks to fill up. now my outside door handle broke and autozone doesn't sell them when it rains it pours.

 

fixed the outside door handle schucks(o'reiallies) had them

 

SeaFoam doesn't contain PEA, the corrosion tidy upper in Techron, so for best results in removing corrosion on the fuel level sending units windings & wiper contact, use Techron Concentrate Plus at the prescribed 1oz/gallon treat rate, at the pump before filling so to get good mixing, with one of the above fuels that also have PEA in them. This will raise the treat rate 10X above pump gas alone & is often enough to see results in one tank.
Let us know how it goes with the fuel level gauge reading.