Fuel Sender Rebuild

[HWYCRZR]

Installed my old sending unit. Every thing tested right on the bench. But now that it is in and full of fuel I am barely reading 1/2 tank. The sending unit is sitting at 26 Ohms so the gauge signal is correct. I need to get a scope in the tank to see where the float is sitting.

 

[live4theking]

I need to pull mine out and check the readings. With a full tank mine reads about 5/8 of a tank. I'm hoping it just needs the arm adjusted.

 

[Big_John]

My adventures
Gas Gauge Fix

 

[HWYCRZR]

My adventures
Gas Gauge Fix

I have that bookmarked as a last resort.
But Dammit, it is driving me nuts that I cannot re-store the Chrysler engineers perfection (LOL). So instead of spending my hard earned money on this little calibration device, I spent it on a Ryobi Phone scope.
I am sticking it in that damn tank to see where my float is sitting. (I won't get it until next Thursday).
I tested my float before I put it in. Dry and no air bubbles. I didn't see much difference in shape between the old an new tank, so that shouldn't be it. My tank is full ( I can see fuel in the neck. The one thing that could affect it a little would be tank angle. If my springs are really sagging, I wouldn't be able to fill it to the top, but that would likely make the reading less than 1/8 of a tank off.
I am not ready to give up yet. I have found it takes me less time to drop my tank to change and adjust the sending unit than doing it while the tank is up. I am a believer that 80% of peoples issue with their retaining ring and gasket is improper installation. It has now happened twice that I had a leak after installation. By not keeping the retaining ring perfectly centered it wants to slide the sending unit just a little and prevents a good seal.
Myth buster alert. I measured the thickness of my original ring vs a couple of spares and the one that came with my tank from Vans. The Vans one measures 1/16" thick, my original and the other replacements are thinner at about 3/64" so a 64th of an inch thinner.
I will be back and bring pictures with my new scope.

 

[3175375]

I have that bookmarked as a last resort.
But Dammit, it is driving me nuts that I cannot re-store the Chrysler engineers perfection (LOL). So instead of spending my hard earned money on this little calibration device, I spent it on a Ryobi Phone scope...

...I will be back and bring pictures with my new scope.

The positive is that you can moonlight as a proctologist as well!

 

[HWYCRZR]

I caved

I hooked it up tonight. I was able to do it without cutting wires. For the gauge signal I pulled the cowl vent cover and pulled my sending unit wires out of the plug. I then put packard terminals on the sender input and output from the Meter Match. Input plugged into connector to grab signal from sending unit. And the output connected to original gauge input. Then I wrapped and routed the wires with the original body harness up into the dash. For power I had an extra terminal on my solid state dash regulator that I plugged into. Switched power. Then ran a ground wire to connect with the ground on my steering column.

 

[HWYCRZR]

I first calibrated the meter match with an almost full tank. I set it to full. Then I decided to top it off it took less than a 1/2 gallon. When I turned the ignition back on it showed way over full. (Did my sending unit all of a sudden break loose and start working?) I should probably crawl under tomorrow and ge an Ohm reading. I re- calibrated the Meter Match back to full. Real easy to set. After about 200 miles I will have to check where the gauge is sitting. I want to run it out to set the low end. I probably won’t set any mid points.

 

[HWYCRZR]

I need to do some troubleshooting.
Static on the bench my fuel sender has the right parameters. but of course once in my tank I could only get a half full reading. Now that I have the meter match hooked there is a lot of movement. Not sure if I have not set the low end and the stored value is way off so any little movement is exaggerated? Every time I would slow down the fuel level would go up and then settle back down after stopping. It would drop lower when I took off and then go back up. I am going to try to set my low end with my little gauge checker. My low end was 64.4 Ohms. I will try that.

 

[traintech55]

The older mopars were famous for the gauge moving under hard acceleration.

 

[HWYCRZR]

I am moving my trials and tribulations over to a new thread so I don’t clutter this one that is specific to the sender rebuild.
Fuel Sender calibration using Meter Match

 

[HWYCRZR]

The older mopars were famous for the gauge moving under hard acceleration.

But I was getting about a half of tank fluctuation. I think I figured it out on the link above.

 

[garyh]

Has anyone sent out their sender unit for a rebuild ? Ballpark price ?