Inaccurate Fuel Gauge

[perko]

Hi everyone,
I've got a problem i wanted to run by the heads on the forums. I put in a new tank/lines/sender because they were rusted to hell. I put in a spectra fuel sender, and now the gauge works but It reads 3/4 full when there's a full tank, and empty when there's 10 gallons left. Any ideas on how to remedy this?

 

[67Dart273]

There are hundreds of threads on this. Basically, the repop senders all seem to suck

You need to........

1....Get test resistors to duplicate the old Mopar test tool and see if the gauge, limiter, and so on is working regardless of the fuel sender

2...You may, if you take enough time, be able to bend / adjust the new sender to be more accurate

3...Last there is a device marketed which will scale the sender to the gauge, which you can program

Here's a member who built a prototype

Gas gauge calibration unit

and also posted in that thread is the commercial one someone is selling:

Here:

Solution to Fuel Gauge/Sender Problems

 

[66fyssh]

When I bought my car the gasoline gauge and temp gauge didn't work. I replace the IVR with a 7805 regulator. Temp gauge works good but the previous owner replaced the gas tank and sender. Now my gas gauge reads 7/8 when full. Not certain about the empty side, but I think it's pretty close. It's good for now...

 

[Mr.FT]

I had somewhat the same problem, I got the gauge really close with metermatch. Google it, the unit is programmable it hooks up in line with your sending unit to gauge wire. I started with a full tank of fuel, set the meetermatch so the gauge read full. Ran the car till it was close to empty (By milage) pupped out the rest with an elect. fuel pump. Then I added @3 gallons and programed the meetermatch so the gauge read a little above Empty. It tracks fairly accurate but I know when to refill. These repop senders really are inaccurate!!

 

[Oaktree]

These repop senders really are inaccurate!!

Not that the factory ones were all that great either. Both the '70 Dart & '71 Duster I had back in the day would read 3/4 full when I really only had about a half tank. By the time it read 1/4, it was a good idea to look for a gas station soon.

 

[67Dart273]

My B body cars were quite a bit better than that, but certainly not very linear. In the early 70's I owned a 64 426 Dodge, a 69 383 RR, and a 70 440-6 "As I remember" the empty end was the opposite....you could "run it on the peg" for a bit without running out.

 

[perko]

sweet. Thanks everyone!