B210 Fuel tank sending unit part swap???

[BestyBlue77]

My fuel tank sending unit in my 1977 B210 Coupe is toast. I can't seem to locate another one. Can that sending unit be swapped out from another model of Datsun? I've seen some sending units on eBay for z-cars. Would one of those work? Please help!

[datzenmike]

I imagine the senders are all the same but the arm length, bends and floats may be different depending on application. I've interchanged 620 and 720 tanks and gauges and they read the same. 

 

The resistance values are...

 

10 ohms or less is full

25 ohms is 3/4

40 ohms is 1/2

56 ohms is 1/4

80 or more is empty

[Crashtd420]

Careful with some of those ebay ones, I bought one that was suppose to be for my 521 and it was not even close to correct.... the arm was all wrong...

Look for one with a similar arm and you might get lucky.... 

I placed my old one on a piece of cardboard and drew the arc it made then placed the new one on and compared the arc.... I tried to bend the new one to match the old but was never successful. .. got lucky and rehabbed the original... 

[datzenmike]

As long as it reads empty properly. ?

[Crashtd420]

18 hours ago, datzenmike said:

As long as it reads empty properly. ?

Ya that's what I couldn't get mine to do... with no gas the float was touching the bottom of the tank.... I would be empty at a quarter tank.... and full would only read 3/4.... 

[datzenmike]

Bend the float lever up. You might hit the top of the tank and only read 3/4 full when full but it would at least let you know when you were nearing empty.

[Duncan]

There are places that can rebuild them.  I had my 510 wagon sender rebuilt a few years back for about $100.  I don't remember where I sent it, but it took about ten days to get it back, and it still works great..

[BestyBlue77]

3 hours ago, Crashtd420 said:

Ya that's what I couldn't get mine to do... with no gas the float was touching the bottom of the tank.... I would be empty at a quarter tank.... and full would only read 3/4.... 

My daily driver almost never reads full even when it's spilling over the top. Lol. Oops! BUT like you guy mentioned I've never once run it out of gas in 20 years of owning. Haha. That's a win in my book. Yeah, I'm going to clean it up and try to at least swap the float for a new one.The electrics look okay. We'll see. Thanks for the info guys! That's just whay I was hoping for.

[datzenmike]

The sender will read more accurately if the tank is symmetrical. My goon tank is under the car and has a spare tire notch. The top is larger than the bottom. I can drive about 80 miles before it begins to read below full.

[difrangia]

Here's some good basic information on fuel metering systems.

 

http://www.tanksinc.com/index.cfm/page/ptype=results/category_id=159/mode=cat/cat159.htm

 

If your tank is 6" or more deep this may work according to what datzenmike posted for ohm values and if your tank has the SAE 5-hole mounting opening. They're sold in 1" increments length.

 

https://shop.classicinstruments.com/sn39t

 

I just recently acquired one of these from Classic Instruments in the 0-90 ohm series and 6" long that mounted right in the tank of our 1964 320 Datsun pickup and it works fine. The 320 tank measured 6 5/8" deep. Cost me about $97. No rod and float to worry about getting bent and oriented correctly on this little puppy. There is a sliding float inside the aluminum tube. These are made primarily for use in fuel cells I believe but if you can nail down the correct ohm range and length it might be a drop right in deal. 

Edited November 6, 2018 by difrangia