• The Roadster Factory Recovery Fund - Friends, as you may have heard, The Roadster Factory, a respected British Car Parts business in PA, suffered a total loss in a fire on Christmas Day. Read about it, discuss or ask questions >> HERE. The Triumph Register of America is sponsoring a fund raiser to help TRF get back on their feet. If you can help, vist >> their GoFundMe page.
  • Hey there Guest!
    If you enjoy BCF and find our forum a useful resource, if you appreciate not having ads pop up all over the place and you want to ensure we can stay online - Please consider supporting with an "optional" low-cost annual subscription.
    **Upgrade Now**
    (PS: Subscribers don't see this UGLY banner)
Tips
Tips

Fuel sender, fuel gauge 100 4

Jerry

Darth Vader
Gold
Country flag
Offline
I was helping a friend with his 100 4. The fuel gauge just came back from Nosinger gauge repair. Looks beautiful. I hooked the unit up with the correct wires as per the wire chart and the needle went to full right away. The tank is about full , but this was so fast I am wondering if there is an issue. I have asked the owner to siphon out gas to see if it changes the needle but I also have a quesiton:
I noticed there was seepage around the sender unit in the tank. He ordered a new gasket for that. But, typically when there is seepage, there is also gas within the coil area. Will that affect the reading?
PS: I did put an extra ground to the sender since the fuel line had been cut going to the coil and rubber hose put in which would have killed the ground in that direction.

Jerry
 

steveg

Yoda
Gold
Country flag
Offline
Left, my tank sender currently. The wet stuff is 11-year-old hylomar. No gas leakage after 11 years.
Current sender is OEM unit, installed Nov 2006. I replaced the original phillips screws with panheads to further spread the pressure.
Right, original Moss repro sender install, May 2005. Washers are Dorman bonded sealing washers.

PS - since you have a ground wire, suggest pulling the sender out and operating the arm by hand to make sure the gauge follows it.
If nothing happens to the gauge, it's either wired wrong at the gauge or the little internal wire to the gauge wire post may have been broken.
PPS - make sure the float arm points toward the front of the car.
It's normal for the sender unit to be filled with gas.
TankSender1117.jpg
TankSenderCloseup0505.jpg
 
OP
J

Jerry

Darth Vader
Gold
Country flag
Offline
I think we need to pull it and test it then. Have to change the gasket anyway. Thanks Steve.

Jerry
 

Michael Oritt

Yoda
Gold
Country flag
Offline
Jerry--

I've had the best results in stopping leaks at the sender by installing a new cork gasket.

When you are doing your testing of the sender the needle should of course change as you move the arm up/down. Though some have figured a way to dampen the sender's signal with a resistor or some other component to make it less jiggly the odometer should give you an acceptable indication of the amount of fuel remaining. My car's mpg is a consistent 23-25 and at 200 miles I am looking for a gas station. at 250 looking hard!
 

dklawson

Yoda
Offline
I hooked the unit up with the correct wires as per the wire chart and the needle went to full right away.

A 100-4 would be old enough to have the magnetic gauge system. It's fuel gauge should snap immediately to whatever reading is appropriate as soon as the ignition key is turned to run. That would be normal.

You can confirm (more or less) normal gauge function by jumpering to ground the "T" terminal on the back of the gauge. That should peg the needle at/below the Empty marker. Remove the jumper and the green/black wire from the sender and the gauge should go to (or above) the Full marker.
 

Bob_Spidell

Yoda
Gold
Country flag
Offline
... I've had the best results in stopping leaks at the sender by installing a new cork gasket. ...!

Sometimes, the flange on the sender is warped due to a DPO cranking down on the screws in order to stop a leak. And aftermarket tanks might not have a perfectly flat flange either. I solved this problem on our BN2 by stacking two cork gaskets with a THIN film of fuel-resistant sealant--Permatex makes one--on all surfaces. You'll need longer screws.
 
OP
J

Jerry

Darth Vader
Gold
Country flag
Offline
Thanks for the help group. I will inform the owner of your recommendations and we will get it fixed!
 
Similar threads
Thread starter Title Forum Replies Date
FlyingCat Spitfire Fuel Sender Unit Triumph 2
JPSmit Fuel tank sender - how does it work? Spridgets 4
Healey Nut Fuel Sender Austin Healey 3
Lutz Kramer Fuel gauge and sender unit for BJ8 Austin Healey 2
sim fuel tank sender reading full all the time Spridgets 9
R Fuel sender internal wire Austin Healey 13
H TR2/3/3A Fuel sender or gauge? Triumph 8
L Fuel Tank sender 100/6 Austin Healey 8
S fuel sender Austin Healey 7
rjc157 Fuel tank sender Austin Healey 13
S Hot tip: seal for fuel tank sender Austin Healey 9
T TR2/3/3A fuel sender Triumph 12
J Orientation of sender in fuel tank Spridgets 2
T Fuel Gauge & Sender Unit Austin Healey 5
I Fuel sender unit testing Triumph 2
Jeepster New fuel sender unit Austin Healey 9
J Busted Fuel Tank Sender Unit Screws Austin Healey 7
M Fuel sender unit float leaks Triumph 8
G MGB Fuel sender '71 MGB MG 9
martx-5 TR2/3/3A TR3 Fuel Sender From Moss Triumph 8
T TR6 Bolt size/thread count for fuel sender TR4/TR6 Triumph 16
pjsmetana Fuel Level Sender needed... Triumph 5
T How best to test a fuel sender off the car? Triumph 10
M Fuel Tank Sender? Triumph 2
Morris Fuel tank sender Spridgets 3
newmexTR3 fuel gauge/sender wiring Triumph 7
ncbugeye Can a Bugeye fuel tank sender be restored? Spridgets 7
NutmegCT TR2/3/3A fuel gauge / sender TR3A Triumph 25
Randy Harris Fuel sender gasket - replace w/full Tank? Austin Healey 8
healeynut Ebay Fuel Tank Sender Austin Healey 5
jhorton3 Fuel Gauge Sender Spridgets 4
T TR6 Repair or replace TR6 fuel level sender unit Triumph 4
G TR6 Fuel sender resistance for TR6 Triumph 1
A Fuel tank sender - direction to install? Austin Healey 3
dklawson TR4/4A TR4-TR4A Fuel Sender Resistance? Triumph 3
L Fuel sender specs... inaccurate gauge?? Spridgets 4
B Fuel Tank Sender Austin Healey 7
TypeRboy Fuel guage sender for Elans Lotus 0
B TR4/4A AC Fuel Pump Priming Lever Stuck Triumph 10
A TR6 How many fuel filters-TR6 Triumph 20
Q TR2/3/3A 61 TR3A Fuel Pump Triumph 4
A TR2/3/3A Those round fuel line clips Triumph 2
SherpaPilot TR6 Preping a New Fuel Tank Triumph 7
RJS TR4/4A Tune Up Order - Fuel and Ignition Triumph 5
G MGB ugh.....the fuel gauge went to *** again! MG 8
D Wanted Square body LCS fuel pump Austin Healey Classifieds 13
D Wanted Wanted square body fuel pump Jaguar Classifieds 0
J MGB Jet Tube to Float Chamber Fuel Leak MG 7
roscoe Fuel Gauge Austin Healey 0
D TR4/4A TR4a Fuel Pump Triumph 10

Similar threads

Top