Hi all first post here. Recently acquired a ‘31 Plymouth coupe. Complete rebuild and noticed the fuel gauge was not working. It has a Jaz Products tube sending unit that the cork float seems to be getting stuck a bit. All electrical is fine after testing it’s just the float. Anyone have experience on where I can find a suitable replacement? thanks so much looking forward to the site!
Thanks Nick. I have looked through their site and I have an email inquiry to them about possible replacement as I have not found any part replacement options directly from Jaz other than gasket and nut ring. Also looking for any potential aftermarket replacement options.
since most of us have never taken apart one of those senders to see what the float looks like, perhaps you could take it apart and post some photos, so we can see. Then we might be able to offer some useful suggestions.
Like "squirrel" says best take it apart then you may find a way of sorting it out to stop the float sticking
Is the float actually stuck? I've had one of those for 20+ years in my 57. It is slow to move, but it does move. I see the problem as fuel moves around in the tank, it causes the float to rise and fall. Since the float is inside a tube, that must empty and fill, the gauge may appear not to move. The company Tanks has a float and lever sender that will fit the bolt circle of the Jaz unit. https://www.tanksinc.com/index.cfm/...t_id=276/category_id=184/mode=prod/prd276.htm
Oops! Didn't notice before, you have a six bolt flange. Mine is five. So the Tanks Inc unit will not work.
I'd think that sender works the same way this mechanical fuel gauge works. The float rides up piece of metal with a twist in it and on a mechanical unit turns the needle and on an electric gauge moves the contact across the resistor.
I have used a tubular gas gauge sender for several years and really like it. My gauge now accurately reports full when full and when it shows near empty, believe it! Ordering a replacement is easy. You need to know the ohm range of your dash gauge. Then order the longest tube that will fit in tank without touching the bottom. Do you know the ohm range of your gauge? How deep is tank from gasket surface to bottom? This is what I used https://isspro.com/products.php?productid=1049
It is exactly that, the only difference is that it is enclosed in an aluminum cylinder. I was looking just to replace the float. Ives found full unit replacements but in the 150+ range from Jaz. Obviously I don’t need to go same brand but that just a point of reference. I will test the Ohms on the gauge side. But that essentially the same design minus the cylinder enclosure.
That six bolt sending unit seems to be unusual. What gas gauge do you have? Is it an aftermarket brand?
Then you need a 240 - 33 ohm fuel sender. This is pretty much standard with aftermarket gauges. Does your fuel cell use six bolts or five bolts to secure the sender?
Are you able to attach a digital volt/ohm meter to the leads on the old sender? Set the ohm range to 200 ohms. Then manually move the float from full to empty and see the ohm range on the meter? That should help us see what the dash gauge range is.
Looking through their site, I only see 5 bolt setups. I will need to reach out and see if they have either a 6 bolt (unlikely) or an adapter to convert the bolt pattern.
Cork? How old is it? Have you taken it apart to see why the float is stuck? I thought Jaz was race car stuff.
This is an adapter. Note that the six bolt circle is not symmetrical. Holes are not equally distant. https://www.speedwaymotors.com/Spee...k-Sending-Unit-Sender-Adapter-Plate,5865.html Is your tank non symmetrical? Or can your existing sender be clocked any of six different way?
Yep, that is the same one I found as well. Luckily they have a retail store here so I can go down and check it out (assuming it is in stock). I noticed that the Jaz offerings is only 5 bolt now. So they must have changed the config at some point. I am going to pull out the sending unit and get the ohm range, measure etc tonight. I'll order from ISSPro (thanks for the link). I will check the hole spacing as well. I have read a few other places that 6 bolt are usually not symmetrical.
Not sure how old the sender unit is. Car is a '31 Plymouth, but complete frame off rebuild. Judging by looking through Jaz site and no longer offering anything that looks like it I have to assume it as some age to it. I have taken it apart, cleaned, bored our the rail guides a tad to see if that would improve the glide on the tracks. It started working a bit after that. The Cork may have just lost some of its buoyancy over the years as well. I am going to do some tinkering tonight in a observable container with water.
That could mean many things, to different people. I don't understand why a rebuilt 1931 Plymouth would have a Jaz tank. That's modern race car stuff. Or is it the original tank? A mix of old and new? I'm confused about what's going on. Saturated cork doesn't float very well. If at all. Also, I agree with @squirrel in post 4 above.
This site has the assymetrical hole distances for this 6 to 5 adapter. https://www.speedwaymotors.com/Spee...k-Sending-Unit-Sender-Adapter-Plate,5865.html
Here is is completely taken apart. Surprisingly it appears to be magnetic. I was expecting the center twisted post to attach the electric sender somehow. Clearly not how it works. also six screws appear to be semetrical
Couple choices. One, make a symmetrical 6 to 5 adapter, or continue to shop for one. Two, replace the Jaz fuel cell with a Tanks Inc. steel fuel tank, which might be the better long term solution. Thoughts?
Hey Pprather, sorry man been a HEAVY travel two weeks for me. So checked out a 6>5 adapter here locally and as expected non fit the bolt pattern. So instead of going the full replace route just yet I actually found a replacement cork float that required a little “shaving”. Installed that into the existing sender and viola it appears to be working now. Potentially a bandaid fix but will do until I find/need a long term replacement.
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