Fill ’er up!

[Mark]

Each time since I’ve owned my London Roadster that I filled her with gas I spilled fuel if I tried pumping at regular speed and always at the end when the automatic shut off didn’t work and fuel spilled on the my fender and floorboards.  Tonight, I filled her with the handle turned upside down and had only one small leak while filling.  It still over flowed to tell me if was full, so I’m a mess to clean up before I drive away from the pumps.  Each time I fill up, my gauge reads on 3/4 full, so I don’t know how much it will really hold.  There is a vent tube for it.I think I need a new gauge, too.

[edward ericson]

For the gauge issue, maybe pull the fuel sender and bend the float rod down a bit. Costs nothing and it might work.

For the spillage: sorry. I was a gas pump jocky in the 1980s and recall it as the era of spilled gas. For some reason, cars made from the late ’70s to the late ’80s very often had this problem. No reason to think the kit cars would be any different.

Bridget fills by opening the hood; the fuel filler is on top of the stock Bug tank and the neck is only a couple inches long (it was relocated from the opposite corner of the tank, according to the build instructions). Inconvenient a little, but works flawlessly, as you can easily see how much gas is in the tank. Auto shut-off works too.

So if you want to re-think it, there’s a model that works.

PMOSSBERG40709.5085185185

[Tom Colello]

Had a similiar problem with my Allison with the auto shut off not working. The Allison is a little different in that the filler is the radiator cap. Yep you guessed it. Fuel spilled down my freshly polished grille. Fortunately it wasn’t very much.

You should see the looks I get at the filling station with a gas nozzle sticking out of the radiator cap.

I told one guy who was looking at me strangely that “I wasn’t a car guy and I think this is where my wife told me to put the fuel.”

He didn’t reply!

[Mark]

Gunfighter, that is hilarious!!  I’m laughing out loud as I type this.

[Mark Hendrickson]

The fuel gauge is fine…it’s your sender if it’s not reading correctly.

The float arm can be adjusted by removing the sender and measuring the distance to the bottom of the tank. Set your float height about 1/4″ higher (shorter). It should do the trick.

The sender is just a variable resistor like the ones that were in slot car controllers. The gauge is just an ohm meter reading the resistance in the current passing through that resistor.

If the resistor has a “dead spot”, it could also cause the gauge inaccuracy.

[Paul Mossberg]

Hey gunfighter, Classic Roadsters Ltd.’s VW based TDs fill the same way as the Allison, through the “radiator cap” 

I’ve had gas station jockeys try to pull the fuel hose from my hands when they see what I’m about to do.

Mark is right about the problem being with the fuel sender and not the gauge. Never reading full is likely due to one of three things:

• You may never actually be getting the tank full because of your back-flow issue. The sending unit may be fine!
• The float may have started to deteriorate and become saturated with fuel. That would make it heavier, it would not be floating on the top of the fuel, and your gauge would be reading less than full.
• The resistor may have a dead spot.

To check the sending unit:

• Disconnect the batttery. I MEAN IT! Disconnect the battery.
• Disconnect the power line to the top of the sending unit.
• Remove the sending unit.
• Do a visual check on the resistor, jsut make sure it’s all clean and making good contact throughout the range of motion
• Get a couple lengths of wire long enough so you can see the guage while holding the sending unit. (This also gets you away from the now open gas tank. Fumes and sparks are not a good combination.)
• Run a ground line from the sending unit mounting to a good groundon teh car.
• Connect the power line.
• Reconnect the battery.
• Move the sending unit through its full range. Slowly. And watch your gas gauge while you do.

If the gauge needle moves ok, your sending unit is fine.

If not, you may need to replace it. But…

The London Roadster has a custom tank. Do you have the stock VW sending unit? It may just need adjustment. It may also NOT fit the tank!

I lived with that for years. Gas gauge needle moved ok, and showed full when the tank was full. But would be on empty when my tank was half full because it could not be adjusted to properly fit the tank. I finally bought a universal aftermarket sending unit. And bought the wrong one because I assumed they were all the same.

The VW uses an 75 ohm sending unit. Make sure you buy the right one. 10 ohms full, 75 ohms empty.

Here’s a good site with even more info:

http://www.midsouthvw.com/TechTips/tech_tip_FuelGauge.htm

And here is one source for a 73 to 10 ohm sending unit:

http://www.tanksinc.com/index.cfm/page/ptype=product/product _id=276/mode=prod/prd276.htm

The “ORG” unit, bottom of the page.

PMOSSBERG40710.5695717593

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[Mark]

Thanks Paul.  This goes beyond the typical maintenance I’ve ever done on a VW engine, but it sounds simple enough to follow your directions.

[Mark]

All of my other gauges in the car are VDO. Only the fuel gauge is not identified, but it looks like it belongs with the set.  Short of pulling it out, is there any way to tell what make it is?  If it is a VDO gauge, wouldn’t I want that one instead of the ORG?

[Paul Mossberg]

It would work with the guage.

My only question is, will it work with your custom tank? If the VDO sending unit is like the stock VW, you may still have a problem.

That is why I went to a generic sending unit, that I could cut to the exact dimension needed for my tank.

PMOSSBERG40710.6670023148

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[edward ericson]

I just did the gas gauge on Bridget. Removed the old Classic Instruments gauge–which never read full–and replaced it with the in-speedo gauge from a ’72 Bug.

Turned out the used speedo I got had a bad vibrator too, and the sending unit for the CI gauge was no good for the stock VW gauge. So I followed these troubleshooting tips (same, really, as Mark’s) and bought the sending unit and the vibrator. Here’s my installation saga.  It was super easy.

Now all is well–though I think I’ll need to go in and bend the rod back up, since she’s reading full until about half empty. My bad…

[Paul Mossberg]

Here is another source for 75 ohm empty/ 10 ohm full fuel sending unit thatis adjustable for tanks from 6 to 24 inches deep (second one on the page):

http://www.egauges.com/vdo_send.asp?Sender=75_10ohms

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[Hugh Coffey]

What brand is your gauge? The VW sending unit is 10-80 OHMs, and was made by VDO. But many of the after market gauges such as VDO Cockpit Royale uses a 10-180 ohm sending unit. You have to match the unit to the gauge, because it is just an analog ohm meter as previously stated by others. The sending unit also come in different sizes, for different tanks. You need to measure the tank to seethe depth and get one that can cover that range. The One I am restoring had a gauge problem, the had a gauge built for a vw snde and put a VDO sender on it and it is all messed up and will not go over 3/4 tank. The VDO sender for instance is rated 10 ohms empty and 180 ohms full. so if some body replaced it with one that is rated 10- 90 it would never get above 3/4. It is just not just 1/2 = 90 it depends on the float how long the arm is. You need to make sure that you match the gauge, sender, and tank. If you buy a cheap universal sender, it will probably innaccurate. You get what you pay for. Many of the kit car companys used VDO Cockpit Royale gauges, because they wanted that Old Time look. Hopefully you can solve your problem easily.

Good Luck

[Paul Mossberg]

GrandpaJo is right about needing a correct match. We all agree on that.

He is right about VDO’s Cockpit Royale series too. It’s not available in the 73/10 range

But VDO does have modern and classic gauges that match the VW 73 empty/10 full ohm readings.

MGLondon – The bottom line is there must be a mis-match in your car. It’ll be a pretty easy fix once you figure out where the mis-match is.

PMOSSBERG40719.9921296296

Paul Mossberg
Former Owner of a 1981 Classic Roadsters Ltd. Duchess (VW)
2005 Intermeccanica Roadster

If you own a TDr and are not in the Registry, please go to https://tdreplica.com/forums/topic/mg-td-replica-registry/ and register (you need to copy and paste the link)

[newkitman]

MY kit came with the gauges and the fuel sender unit. Is that normal for the kit manufacturer to do that AND is that a guarantee that they match? I’ll ohm out the sender this afternoon and see. How do I tell what the resistance of the gas gauge is SUPPOSED to be?

Thanks GrandpaJo.

newkitman40720.5960532407

Allen Caron
VW based 53MGTD - "MoneyPenny"
"If one thing matters, everything matters" - from the book The Shack

[edward ericson]

The gauge MFG should be able to tell you what the ohm range is. I’d take all the numbers off it and go to the Google. The Samba probably has an opinion, which may or may not be the correct opinion.

You also might be able to figure it out using a good rheostat switch (like maybe the dash light switch) but that’s just my guess.

[Author]

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