Autometer fuel gauge & Autometer universal sending unit install (1 Viewer)

[MBOffroading]

So, in my quest to build a new gauge panel, (that and my fuel sending unit was bad) I started buying gauges, today I received my AM Fuel Gauge & AM Universal Sending Unit
and proceeded to install the SU, first thing I noticed was I had to modify the plate (screw holes didn't line up), I checked the tank depth, STEM length and float length, cut the float arm to the recommended length, installed and wired up the gauge.

After turning the FJ on, with gas in the tank (not much, about less than 1/4 tank full, I plan to fill the tank tomorrow morning), the gauge barely moved up to the 'E' on the gauge.

My only concern is the setup, it was hard to get the tank depth, I figured it at 9" (bottom of the hole for the sending unit mount, to the bottom of the tank where the dip is at the bottom).

I want to know if anyone has experience with installing the above listed parts in a stock fj40 (1974) tank.

 

[rchandler]

I used this on my 66 Autometer gauge No problems

Summit Racing SUM-290260 - Summit Racing® Fuel Sending Units - Overview - SummitRacing.com

 

[MBOffroading]

The fuel gauge I have is listed at 240/30 (f&e), so the gauge wouldn't work with that SU.

 

[fieldsken1]

dont you have the original one??? use a tape measure

 

[MBOffroading]

dont you have the original one??? use a tape measure

The original sending unit? If yes, I have the original. Not really sure what you mean by measure it.

 

[fieldsken1]

The original sending unit? If yes, I have the original. Not really sure what you mean by measure it.

just compare the floats. how far down and up they go

 

[MBOffroading]

Maybe I'm missing something, but how will that help me?

According to the documentation, if I don't have the lengths right, it wouldn't give the correct reading.

Also, the float unit on the OEM SU is at the top, as were the AM SU is located at the bottom.

 

[fieldsken1]

i dont know what the stock one looks like. is there something thats goes down as you use the gas and goes up as you put more in. at the extreme bottom that would be mt right. just measure from that to the top of the sending unit and set the new one at the same measurment. that should tell you when the tank is mt right

 

[MBOffroading]

i dont know what the stock one looks like. is there something thats goes down as you use the gas and goes up as you put more in. at the extreme bottom that would be mt right. just measure from that to the top of the sending unit and set the new one at the same measurment. that should tell you when the tank is mt right

Ok, I think I get it now.

The stock SU looks more or less like this

http://ep.yimg.com/ca/I/coolfj40_2159_5858127

 

[fieldsken1]

when the float is down measure from the bottom of the float to the plate that connects to the tank. set the new one at the same distance thats all

 

[MBOffroading]

Ok, I just went and did that with the stock SU, very bottom, maxed out is 6 1/2" from middle point on the float, to the base of the plate.

Lifted all the way up, it's 2" from the base of the plate.

So what I should do is adjust the float arm and the height of the SU (it's adjustable from 5" to 20") to match the 6 1/2" & 2" mark?

 

[fieldsken1]

let the float hang down and there should be a slide on there just adjust the slide untill you get the right lenght between the float and the ring. you really dont need to worry about when its full just when its mt. you can adjust the slide and you can adjust the rod the float is on

 

[MBOffroading]

Thanks for the info. I'll try that when I get home from work today. I'm hoping I can get it working right.

 

[srgould41]

I recently installed the AM sender and gauge. Mine reads correctly. I would recommend measuring your tank depth again and then rechecking your float arm configuration. I don't remember now if I measured to the bottom of the sump well or the upper edge, but I think I used the upper edge of the sump well. I figured if the gauge reads empty and I still have a gallon or two left I would be happier then the opposite.

 

[MBOffroading]

I recently installed the AM sender and gauge. Mine reads correctly. I would recommend measuring your tank depth again and then rechecking your float arm configuration. I don't remember now if I measured to the bottom of the sump well or the upper edge, but I think I used the upper edge of the sump well. I figured if the gauge reads empty and I still have a gallon or two left I would be happier then the opposite.

I plan to fill the tank today on my way home, and see what the gauge says. If it's reading F, then I'll be happy, I would like to get it as close as possible... things like this makes me wish I bought domestic... or relocate a fuel cell to the back.

 

[FishNinJay]

So, in my quest to build a new gauge panel, (that and my fuel sending unit was bad) I started buying gauges, today I received my AM Fuel Gauge & AM Universal Sending Unit
and proceeded to install the SU, first thing I noticed was I had to modify the plate (screw holes didn't line up), I checked the tank depth, STEM length and float length, cut the float arm to the recommended length, installed and wired up the gauge.

After turning the FJ on, with gas in the tank (not much, about less than 1/4 tank full, I plan to fill the tank tomorrow morning), the gauge barely moved up to the 'E' on the gauge.

My only concern is the setup, it was hard to get the tank depth, I figured it at 9" (bottom of the hole for the sending unit mount, to the bottom of the tank where the dip is at the bottom).

I want to know if anyone has experience with installing the above listed parts in a stock fj40 (1974) tank.

I installed this in a rear auxilliary aluminum tank. Before even installing, I hooked it up to my Sunpro gauge and tested it by moving the arm up and down. Worked fine.

I did the same set-up, except my gauge is Sunpro. I just eyeballed it and adjusted the main arm and float arm up and down to see if it matched the vertical range. I erred on the side of being a bit short, so that when the float is all the way down (and empty on the gauge), it's probably half-inch above the bottom of the tank (reserve gas).

Also, are you sure it's not on a different angle and maybe hitting an internal baffle? And, you may also want to try and adding a separate ground wire to an actual ground bolt. Especially if the tank is coated or painted, maybe the sender mounting bolt is not grounding.

 

[MBOffroading]

I tested the gauge prior to putting it in, the SU at full range is more or less 250 full & 30 empty. I verified this with an ohm meter. The gauge works perfect. I know I'm not hitting the baffle, as I have it pretty straight in the tank, and I verified I wasn't hitting anything.

 

[FishNinJay]

Maybe I'm missing something, but how will that help me?

According to the documentation, if I don't have the lengths right, it wouldn't give the correct reading.

Also, the float unit on the OEM SU is at the top, as were the AM SU is located at the bottom.

I think what KKen is saying is that the height of tank is what matters, and each individual sender has different angle ranges. The OEM is near the top of the tank, and the AM is adjustable. You can make the AM like the OEM and put the swing joint near the top, but then you'd probably never see FULL on your meter. I don't have any photo edit capabilities, so I'll do this ol'skool from my phone cam....

These both have the same vertical range, but the universal AM unit needs 2 adjustments, the height of the swing joint assembly, and the length of the float arm.

Hope this helps?? ...

 

[srgould41]

I think he just needs to verify the tank depth and make sure the arm is adjusted correctly per the chart that comes with the sender. It has to be done exactly right or it won't read correctly.

I will look at my documentation when I get home and see if I noted what settings I used on mine.

I think what KKen is saying is that the height of tank is what matters, and each individual sender has different angle ranges. The OEM is near the top of the tank, and the AM is adjustable. You can make the AM like the OEM and put the swing joint near the top, but then you'd probably never see FULL on your meter. I don't have any photo edit capabilities, so I'll do this ol'skool from my phone cam....
[PIC]
These both have the same vertical range, but the universal AM unit needs 2 adjustments, the height of the swing joint assembly, and the length of the float arm.

Hope this helps?? ...

 

[MBOffroading]

I think what KKen is saying is that the height of tank is what matters, and each individual sender has different angle ranges. The OEM is near the top of the tank, and the AM is adjustable. You can make the AM like the OEM and put the swing joint near the top, but then you'd probably never see FULL on your meter. I don't have any photo edit capabilities, so I'll do this ol'skool from my phone cam....
[PIC]
These both have the same vertical range, but the universal AM unit needs 2 adjustments, the height of the swing joint assembly, and the length of the float arm.

Hope this helps?? ...

Not sure if there was supposed to be a pic? It's my first time doing an aftermarket fuel gauge, so I'm trying to get it right. I'm open to suggestions.

I think he just needs to verify the tank depth and make sure the arm is adjusted correctly per the chart that comes with the sender. It has to be done exactly right or it won't read correctly.

I will look at my documentation when I get home and see if I noted what settings I used on mine.

That's more or less what I am trying to do.