Fuel sender

[flyinlow]

Got a new sender for the sender. Ohm readings erratic and incorrect. I assume they can be tested dry?

[green69rt]

Sorry to say, all the repro senders seem to be bad.  Lots of threads on here about that subject.  The MOPAR senders used a very unique resister that the vendors have a hard time reproducing.

[Lennard]

Sorry to say, all the repro senders seem to be bad.  Lots of threads on here about that subject.  The MOPAR senders used a very unique resister that the vendors have a hard time reproducing.

50+ years ago...  easy to produce.
2019... seems to be impossible to produce. 

[Kern Dog]

Here is what I have read:
The originals were designed with a manner of operation where the readings were not linear. In other words, if at empty it read 70 and when full it read 10, (A difference of 60) at half it did not read 40.
The reproduction versions read in a linear fashion and they screw with the gas gauge because of it. Pour 9 1/2 gallons in a 19 gallon tank with a new chink sender and it will absolutely NOT read 1/2 on the gauge.

[Ghoste]

It shouldn't be difficult to reproduce, they simply choose not to and we accept it through continued purchase so why fix it?

[tan top]

Sorry to say, all the repro senders seem to be bad.  Lots of threads on here about that subject.  The MOPAR senders used a very unique resister that the vendors have a hard time reproducing.

50+ years ago...  easy to produce.
2019... seems to be impossible to produce. 

I know makes me mad,
with the advances in manufacturing processed & materials & dare I say knowledge.  the majority of the repop parts are shit compared to the quality fit & finish of  50 plus old parts . they should be 100 times better but the are not   
 

[flyinlow]

Yea, both the Asian senders in the cars work to a degree. Show 3/4 when full, stay there for awhile then drop to empty with about a 1/4 tank. Almost like the float arm is too short.
Better than nothing I guess.

[303 Mopar]

In addition to the misreading, the lock ring is cheap thin crap too.  Be sure to keep your original if possible to avoid leaks.

[b5blue]

If you opened an original you would see the winding's spacing varies. Close at some areas and farther at other. A nuance of engineering lost to re-pop manufacturers.

[flyinlow]

In addition to the misreading, the lock ring is cheap thin crap too.  Be sure to keep your original if possible to avoid leaks.

Learned that the hard way.

[Mike DC]

It shouldn't be difficult to reproduce, they simply choose not to and we accept it through continued purchase so why fix it?

This.

[JimShine]

I posted my discoveries about this a long ass time ago.

The float arm is attached to a variable resistor (potentiometer). There are two major types: log (and inverse log) taper and linear taper. The old ones had a log/offset taper. Modern cars, and these new units, feature a linear taper. I assume they initially used the log taper to factor in the irregular, angled shape of the bottom of the tank. Naturally the fuel level in the bottom is different than towards the middle where fuel has to fill far more area.

I bought one of these newer "corrected" sending units a couple years ago, and it too is still wrong. The ohms range is closer to correct, but it is still a linear taper, which drops like a stone once the fuel level drops into that smaller, lower area of the tank.

My feelings on fixes for this issue are: For a vendor to see what it is going to take to have proper taper variable resistance strips made for these units. Best case scenario is to find a stock one and reverse engineer its resistance strip. Or: have custom made properly calibrated to respond ideally fuel gauges made to respond to the linear taper of the modern replacement sending units. It would entail having a tank set up filled with fluid and gathering ohms ranges sent at several key points in the sweep of the sending unit in relation to gallons in the tank, and having bespoke calibration in the new gauge to respond properly. If they had a "matched" gauge to solve this problem, they would sell plenty to people that currently have functional gauges just so they can gain accurate fuel level readings with their repro sending units.

[A383Wing]

there is a guy on ebay that rebuilds the OE senders to new and working condition.....we had one done last year....still works perfect.....I put his contact info in a couple of the "fuel sender" threads in here....do a search, you will find him

Bryan

[JimShine]

That is great if you have an OE sending unit. Most of us don't. If I had the original, I would have rebuilt it myself.

[A383Wing]

That is great if you have an OE sending unit. Most of us don't. If I had the original, I would have rebuilt it myself.

then find an OE unit and have it rebuilt....

[A383Wing]

this is the company that we used.....

I have used John Wolf and Co to rebuild sending units and have not used the new units that do not work right. They have a 3 day turn around and you get your sending unit back all rebuilt and they work correct. The phone is 440 942 0083 Willoughby Oh. I have sent units there for a number of years