fuel tank sender for a 311
 

I have a 1987 311 that the fuel gauge stopped working (reads zero). I jumped the tank leads and the gauge went to full with the key on. With key off and an ohmeter between the tank leads, meter read 0 ohms and read infinity when key was turned to "on". This leads me to think it's the sender. So here's the questions: 1) Am I right in guessing the sender? 2) Is there a source that can tell me what VDO sender was used in '87 311s? Does Formula still keep track of this? Is there another source for info and parts? I can't match the numbers on the sender with the VDO catalog kept by the original owner. It has the 2-1/8" bolt pattern and the markings on the sender are (other than "VDO" and "Made in Germany") are "21/130", "12/5/98", and "786". 3) I tried to remove the tube-type sender but it was too long and bumped into fiberglass before it would clear the tank. Has anybody replaced a sender? How did you do it? Hopefully without disassembling the boat! Any help anybody can tell me would be greatly appreciated! Thanks!

Formula keeps pretty good records and has always been able to help me with tech questions.
Removal of the "tube type" sender could be fun:rolleyes: .I replaced mine and had the same problem with hitting the back of the seat. Mine did have a slit cut in the fiberglass which was covered by the upholstery. I was replacing all my guages and had to change the sender too , since it read backward for my new "American" guages.
If I removed some of the panels from the seat back I could pull the sender staight up. But since I was using the float and arm type I simply forced the old one out:o

I replaced mine with a Gaffrig unit. Works great. You do have to set them up and adjust them that can be a pain but they seem to be very accurate and there is no more arm that comes off their unit.

Jon

Thanks for all the help! I called Formula (Thunderbird's tech assistance @ 260-724-1412) and they found the VDO number for the sender no problem. I found a website called "egauges.com" (located in Detroit) that had a huge selection of tube-type VDO fuel senders (and the gasket) at well below retail. Sort of an FYI to other 311 people, the sender is VDO part #224-066 (sender is marked "82/5/98". It has a 2 1/8" bolt pattern and 17 1/16" length. I also got a number for the F272 sender (Rambunctious asked if I could get the number for his reference while I had T-Bird on the phone) and it's VDO #224-065 (14 5/8" long). Thanks again for the help!

Fisch.... by tube type sender... do you mean like the Gaffrig (no arm????) I need three of them!! One for my Formula 312 & two for my Sonic...
Are the tube type adjustible for tank depth??? Or are they for a specific depth tank???

With the gaffrig ones you need to get the correct length. I took my sender out and measured the depth of the tank and relayed that to Gaffrig and had them make mine. I recall them saying that you should not have more then 1/4-1/2" below the tube to have it read and not have your guage bounce all over. Then there is a potentiometer on the thing to make sure it reads accuratly.

Jon

Is it accurate? I'm tired of gauges that show empty when there is 1/2 tank full of gas.....:eek: Accuracy takes the worry out of the boating equation.....:)

The tube-type in mine is the stock VDO unit. The float runs inside the tube. The replacement was specific size for the 311 and Formula was able to tell me the correct VDO part number and tube length. The original owner kept the VDO catalog from back in '87 and had a note that said the tube VDO were made for the "adjustable" fuel gauge (whatever that means!). I haven't topped it off yet to check if a "full" gauge means a "full" tank. In my search for a source of senders, I remember seeing an adjustable-tube that covered from something like 9" to 24". I might still call "egauges.com" -- they may know something of it or search for "VDO Fuel Senders".

Will do, and thanks for the info.... post the results & accuracy of the VDO unit... !! Please...:D

Just filled the tank after replacing the sender and it works fine right out of the box. The fuel gauge just got to full when the fueling pump shut off. I guess that's OK though I can't vouch for the accuracy of the original (I've never run it even close to empty). It seems the same as before.