fuel gauge peculiarities

[jwholgate]

i have a 1971 F250 that has a quirky fuel gauge.
when the tank is full, it reads 3/4 full.
when the gauge reads 1/4 full, i'm about to run out of gas.
tank is the stock behind-the-seat type.

i replaced the entire sending unit assembly several years ago,
with a Dennis Carpenter product, and still the same thing.

i also put a new voltage regulator in the instrument cluster,
but as i recall that made all the gauges pulse, so i put the old one back in.
the other gauges seem to work fine, after new sending units were
installed a few months ago.

i've been working with the quirkiness for a while now,
but i know there are a bunch of wizards here on these forums,
so i thought i'd run it up the flagpole. thanks for reading.

1971 F250 AT PS AC 2WD

[forrestbump]

More than likely your IPVR needs adjustment. This thread explains the procedure: http://www.fordification.com/forum/view ... a&start=30

[70_F100]

Actually, it's probably a bad gauge.

I had the same problem on the 3/4 reading when the tank was full. So, when I had my dash out last year, I said "what the heck" and installed an NOS gauge I had. Same IPVR, no adjustment. Problem solved.

The IPVR adjustment will probably help, but from my experience, it's not the CORRECT thing to do. Especially true since you say it's not reading accurately on the bottom end of the scale.

Just my

[jwholgate]

i seem to remember trying a different gauge (i found a great deal on an entire instrument cluster on eBay several years ago)
but it's been a while. these are good tips, thanks all. keep 'em coming!

[fireguywtc]

If it is not the gauge it is probably the IPVR. I just replaced mine a couple of days ago and it ulitmately ended up being what was wrong with my gauge. Follow this tutorial on how to trouble shoot to see if you need to replace or just adjust the IPVR: http://www.fordification.com/tech/fuel- ... -units.htm