Fuel Sender

[kps_randy]

Hi all,

Has anyone replaced there fuel sender yet? My fuel gauge was reading full all the time even when i was out of gas. I replaced the gauge and still had the same problem so i checked the fuel sender and sure enough the unit was broken. I need to replace it and didn't want to get another stock unit if there is a better set up out there. Any input would be appreciated...

Thanks,

Randy

[Kinarfi]

Hi all,

Has anyone replaced there fuel sender yet? My fuel gauge was reading full all the time even when i was out of gas. I replaced the gauge and still had the same problem so i checked the fuel sender and sure enough the unit was broken. I need to replace it and didn't want to get another stock unit if there is a better set up out there. Any input would be appreciated...

Thanks,

Randy

I rebuilt rocmoc's sender quite a while back and I'm thinking to build a capacitive gauge one of these days, in the meantime, you can send yours to me and I'll rebuild for cost + postage if you want. Check your gauge by put a test light from the line going to the gauge and ground, if your test light has a small bulb in it use a tail light bulb or a quick short to ground. Should read full. At 47ohm resistor to ground is full, 77ohm is 3/4, 97 ohm is 1/2, 107 ohm is 1/4, and 110 ohm is empty. Yep, said it wrong, 3 ohms is full, 13 ohms is 3/4, 23 ohms is 1/2, 63 ohm is 1/2, 110 ohms is empty.

PM me if you want.

Kinarfi

[ricksrb]

I rebuilt rocmoc's sender quite a while back and I'm thinking to build a capacitive gauge one of these days, in the meantime, you can send yours to me and I'll rebuild for cost + postage if you want. Check your gauge by put a test light from the line going to the gauge and ground, if your test light has a small bulb in it use a tail light bulb or a quick short to ground. Should read full, a 47ohm resistor to ground is full, 77ohm is 3/4, 97 ohm is 1/2, 107 ohm is 1/4, and 110 ohm is empty.

PM me if you want.

Kinarfi

That would be good info to put in one of the pinned folders.

Thanks,

[Kinarfi]

That would be good info to put in one of the pinned folders.

Thanks,

Will do, and I'll add this drawing that I already have in web shots. I also think I said it all backwards. Yep, I did, reread #2

There is a magnetic float in the sender and as the gas level drops it closes the next reed switch down, then lets the upper switch open changing the resistance to ground for the gauge.

[Kinarfi]

Will do, and I'll add this drawing that I already have in web shots. I also think I said it all backwards. Yep, I did, reread #2

There is a magnetic float in the sender and as the gas level drops it closes the next reed switch down, then lets the upper switch open changing the resistance to ground for the gauge.

another suggestion is pull the sender and check with an ohm meter and see if the float is stuck or if the reed switch is stuck or broken and shorted. You can steal a reed switch out of one of those security switches or order from Allied Electronics https://www.alliedelec.com/search/productdetail.aspx?SKU=8080004, after soldering, put some epoxy on it.

Also, if it says full all the time, look for a short to ground in the wiring.

Kinarfi

[kps_randy]

another suggestion is pull the sender and check with an ohm meter and see if the float is stuck or if the reed switch is stuck or broken and shorted. You can steal a reed switch out of one of those security switches or order from Allied Electronics https://www.alliedelec.com/search/productdetail.aspx?SKU=8080004, after soldering, put some epoxy on it.

Also, if it says full all the time, look for a short to ground in the wiring.

Kinarfi

Yeah the epoxy used is very low quality...the epoxy has deteriorated and come loose and the maginet was getting stuck in there. even the switches are junk...they all stay closed....i tryed running the maginet up and down manually and they didn't open or close. took the ohm meter to them and got a 0 read. i would gladly send you the fuel sender Kinarfi if you can work some magic and get this thing working again...hopefully it's not too expensive for your services, but then again i have no problem paying good money if you can turn this unit into a quality sender. =)

Thanks,

Randy

[Kinarfi]

Yeah the epoxy used is very low quality...the epoxy has deteriorated and come loose and the maginet was getting stuck in there. even the switches are junk...they all stay closed....i tryed running the maginet up and down manually and they didn't open or close. took the ohm meter to them and got a 0 read. i would gladly send you the fuel sender Kinarfi if you can work some magic and get this thing working again...hopefully it's not too expensive for your services, but then again i have no problem paying good money if you can turn this unit into a quality sender. =)

Thanks,

Randy

When I was flying, instead of crashing, I looked into the capacitive fuel gauge for my plastic tanks, it amounts to two pieces of metal, 100 sq. in. or so about 1/16 apart immersed in the gas, as the level drops, the capacitance changes and that can be measure and translated into a voltage the gauge can use.

What I need is a source for the metal, ( a tube inside another tube) or an idea of how to make the capacitor, thinking about rolling two pieces of aluminum together with fish line separating them. It all needs to drop through the hole where the current gauge is. Any one have any suggestions?

I think this will be my next project.

Kinarfi

[kps_randy]

When I was flying, instead of crashing, I looked into the capacitive fuel gauge for my plastic tanks, it amounts to two pieces of metal, 100 sq. in. or so about 1/16 apart immersed in the gas, as the level drops, the capacitance changes and that can be measure and translated into a voltage the gauge can use.

What I need is a source for the metal, ( a tube inside another tube) or an idea of how to make the capacitor, thinking about rolling two pieces of aluminum together with fish line separating them. It all needs to drop through the hole where the current gauge is. Any one have any suggestions?

I think this will be my next project.

Kinarfi

Kinarfi,

One other thing....the seal for the fuel sending unit has fallen apart and some of the pieces have fallen into the gas tank. Have you replaced this seal before or know what can be used to replace it?

Thanks,

Randy

[Kinarfi]

I have been in the garage working on the capacitive fuel gauge electronic circuit and I think I'M finished with it, It works very well in real gas, very repeatable and only about an inch and a half in diameter. I'll take some photos and post them later today, I think it can go in where the old one is or be place in the center so it stays more constant when going up hill or down or side hill or level. At present, I plan to mount it in a cord grip, I rolled the aluminum around a 1/2" aluminum tube that will extend through the cord grip for attachment to the circuit. Just need to hook it up and make sure it's compatible with the Trooper's gas gauge.

Here's the design if anyone wants to make their own.

Photos of capacitor and circuit board to follow.

If you roll your own aluminum, you will most likely have different values than I did which may need adjusting of some of the components. The aluminum I used was bought at Home Depot in the roofing dept then cut and trimmed to fit inside the tank. The aluminum, IMHO, need to be detempered by putting in an oven at high heat or in the barbecue, other wise it holds its shape to well, hard to roll and once rolled hard to unroll. If any one wants to build one and needs help, PM me, or if you want me to build you one, PM me.

Kinarfi

[Kinarfi]

I have been in the garage working on the capacitive fuel gauge electronic circuit and I think I'M finished with it, It works very well in real gas, very repeatable and only about an inch and a half in diameter. I'll take some photos and post them later today, I think it can go in where the old one is or be place in the center so it stays more constant when going up hill or down or side hill or level. At present, I plan to mount it in a cord grip, I rolled the aluminum around a 1/2" aluminum tube that will extend through the cord grip for attachment to the circuit. Just need to hook it up and make sure it's compatible with the Trooper's gas gauge.

Here's the design if anyone wants to make their own.

Photos of capacitor and circuit board to follow.

If you roll your own aluminum, you will most likely have different values than I did which may need adjusting of some of the components. The aluminum I used was bought at Home Depot in the roofing dept then cut and trimmed to fit inside the tank. The aluminum, IMHO, need to be detempered by putting in an oven at high heat or in the barbecue, other wise it holds its shape to well, hard to roll and once rolled hard to unroll. If any one wants to build one and needs help, PM me, or if you want me to build you one, PM me.

Kinarfi

Sent the design to a Jim Weir who published the design I modified back in the middle of 2000 in Kitplanes magazine asking for his input and I received his comment today. His comment was

"Sorry, but I just can't comment on individual designs, ESPECIALLY on potentially explosive designs.

Jim"

Perhaps this is a warning that some of you may want to take to heart. To me, it opens another thread / discussion.

Kinarfi

[rocmoc]

Well for a fact every sending unit sends a circuit thu the gas tank every a traditional resistent sending unit. Never really gave it any thought but I have to say, I DON"T KNOW.

rocmoc n AZ/Baja

[rocmoc]

Part of me says if you were worried about the liability of the steering setup, this maybe worse!

rocmoc n AZ/Baja

[Kinarfi]

I finished messing with my Fuel gauge sender and it turns out that it is much, much less apt to start a fire than the factory setup!!! The factory set up can supply over a 1/10th of an amp and a little over 7 volts inside the tank. My set up can't supply any DC voltage and only a few thousandth of a volt of a sawtooth wave.

Anyway, here's the schematic and a picture of the circuit board, not installed yet, but will be shortly for more testing.

It's been another fun little project, and if interested, let me know.

Kinarfi

[rocmoc]

Kinarfi, What is this Super Duper Moderator? What did you do to or for Admin?

rocmoc n AZ/Baja

[Kinarfi]

Kinarfi, What is this Super Duper Moderator? What did you do to or for Admin?

rocmoc n AZ/Baja

That's a secret that only he & I will ever know, but I was so jealous of you for being a Super Moderator. I had to do something about it. So I did and now, I'm the only Super Duper Moderator there is, at least for now any way.

Kinarfi

[rocmoc]

LOL!

rocmoc n AZ/Baja

[Kinarfi]

Finished my fuel sender probe and circuit and adjusted it, may need some more tweaking, but it's good for now. I emptied the tank, took photo, added 1/2 gallon, took photo, added 1/2 gallon, took photo, ....... until full. It got full sooner than I expected. I was expecting to put 10 or 11 gallons in, but at about 7 3/4, it started over flowing, so I looked up the specs and the book says 30 Liters, = 7.92 gallons.

Here's a link to the first of a bunch photos, the first 3 are of the probe prior to putting connectors on.

Here's the link to pictures of gauge after adding gas, 1/2 gallon at a time.

The name of the photo is how many 1/2 gallons are in the tank.

Now, to perfect my cruise/engine speed controller.

Kinarfi

[rocmoc]

Kinarfi, Most parts houses sale a universal sending unit, the old style with the float & arm. Can I use one of these, talking about the ohms? What is the ohm range of the gauge? I can physically make it work!

thanks,

rocmoc n AZ/Baja

Super Super Double Dupper Mod.

[Guest Lenny]

Finished my fuel sender probe and circuit and adjusted it, may need some more tweaking, but it's good for now. I emptied the tank, took photo, added 1/2 gallon, took photo, added 1/2 gallon, took photo, ....... until full. It got full sooner than I expected. I was expecting to put 10 or 11 gallons in, but at about 7 3/4, it started over flowing, so I looked up the specs and the book says 30 Liters, = 7.92 gallons.

Here's a link to the first of a bunch photos, the first 3 are of the probe prior to putting connectors on.

Here's the link to pictures of gauge after adding gas, 1/2 gallon at a time.

The name of the photo is how many 1/2 gallons are in the tank.

Now, to perfect my cruise/engine speed controller.

Kinarfi

Nice Job Kinarfi.

Lenny

[Kinarfi]

Kinarfi, Most parts houses sale a universal sending unit, the old style with the float & arm. Can I use one of these, talking about the ohms? What is the ohm range of the gauge? I can physically make it work!

thanks,

rocmoc n AZ/Baja

Super Super Double Dupper Mod.

Super Super Double Dupper??? Mod. If you play golf, Duffer would work.

The left one is yours. Most universals that I googled go from 33 to 240, but the two links at the bottom would work. I'd use the first one and limit it's travel so you get the 110 ohms when empty. If you have too much resistance the needle will just hit the empty pin before your empty, if you don't have enough resistance, you never show empty unless you paint it on the glass face. If it doesn't go to 0 ohms, you don't show full, you can live with that, it's being empty that we care most about. http://www.jegs.com/i/VDO/918/226002/10002/-1 http://www.jegs.com/i/VDO/918/226008/10002/-1

Kinarfi, The Super Duper Moderator!!!

[rocmoc]

LOL! Thanks Kinarfi.

rocmoc n AZ/Baja