Modified or standard fuel sender unit? Advice please!
Discussion
Hi all,
I've had issues with the fuel gauge reading ever since I bought the car last year, but recently it's been getting worse. Anything less than ~3/4 full and the gauge reads empty. I have checked that connecting the two sender wires shows a 'full' tank gauge, so I'm assuming that the sender is at fault.
I have already searched the forum for tips regarding replacing the sender, but none of the sender units pictures in the threads on this forum match my particular unit...
This thread shows a different sender to mine. I haven't seen any with only the single positive terminal.
It's making me think that perhaps the unit has been replaced by something completely different at some point, or that I haven't seen a picture of the original TVR unit anywhere.
All I would like to know is, if I order the recommended Land Rover Defender sender unit Land Rover Defender sender unit, will this fit the hole in my fuel tank?
See pictures below for details:
For comparison with the thread showing resistance values, my current sender is showing 615 Ohms when the tank is ~3/4 full, so I'm assuming this is faulty as it should be between 20-300 ish (full to empty). Any advice would be appreciated, apart from just leaving it as it is :P
I'd quite like to know how far I can get before running out of petrol this summer!
I've had issues with the fuel gauge reading ever since I bought the car last year, but recently it's been getting worse. Anything less than ~3/4 full and the gauge reads empty. I have checked that connecting the two sender wires shows a 'full' tank gauge, so I'm assuming that the sender is at fault.
I have already searched the forum for tips regarding replacing the sender, but none of the sender units pictures in the threads on this forum match my particular unit...
This thread shows a different sender to mine. I haven't seen any with only the single positive terminal.
It's making me think that perhaps the unit has been replaced by something completely different at some point, or that I haven't seen a picture of the original TVR unit anywhere.
All I would like to know is, if I order the recommended Land Rover Defender sender unit Land Rover Defender sender unit, will this fit the hole in my fuel tank?
See pictures below for details:
For comparison with the thread showing resistance values, my current sender is showing 615 Ohms when the tank is ~3/4 full, so I'm assuming this is faulty as it should be between 20-300 ish (full to empty). Any advice would be appreciated, apart from just leaving it as it is :P
I'd quite like to know how far I can get before running out of petrol this summer!
Thanks for the replies. After a bit more of a thorough search, I have found a couple of posts with senders which look like mine here and here
Before buying anything, I'll check the corrosion between the sender unit and tank as you suggested. It could be that the extra ~300 Ohms or so are down to rust etc. Does the fuel tank need earthing anywhere other than the tab shown in my photo, or is there another earth point I should know about/check?
Cheers for the help
Before buying anything, I'll check the corrosion between the sender unit and tank as you suggested. It could be that the extra ~300 Ohms or so are down to rust etc. Does the fuel tank need earthing anywhere other than the tab shown in my photo, or is there another earth point I should know about/check?
Cheers for the help
I've ordered a new landrover defender sender unit and locking ring. If I'm going to go through the hassle of re-sealing the sender anyway, it may as well be a brand new one! This job has now fallen a little down the TVR list as my alternator has now packed in...
Don't want to change the theme of the thread too drastically, but has anyone got advice on where to source a new one.
The one on my car is exactly the same as this but I don't fancy spending £132 unless this is the only option.
Don't want to change the theme of the thread too drastically, but has anyone got advice on where to source a new one.
The one on my car is exactly the same as this but I don't fancy spending £132 unless this is the only option.
Well... after I was told by a garage that I needed a new alternator, and then taking the alternator out and taking it to get reconditioned, I was then told by the re-con chap that the alternator was producing the correct voltage and working fine.
I've re-fitted it into the car and after lots of searching on this forum I think the root cause is a lack of coil activation voltage to the alternator in order to get it started. Got the multimeter out and realised that the bulb has blown for the alternator charging circuit. Wish I'd checked that first now!
Does anyone have a link for a 5w replacement bulb. I'm not that interested in an LED replacement, I just want the easiest fix to swap straight back in there. My car is an F reg S2 if that helps? Also, how to you get the old bulb out? Do you have to remove the plastic fascia over all the instruments and re-glue it from the front, or is there a way to remove the bulb holder from the rear of the dash. I had a go last night but couldn't seen to pull it out from the back. What a faff!
I've re-fitted it into the car and after lots of searching on this forum I think the root cause is a lack of coil activation voltage to the alternator in order to get it started. Got the multimeter out and realised that the bulb has blown for the alternator charging circuit. Wish I'd checked that first now!
Does anyone have a link for a 5w replacement bulb. I'm not that interested in an LED replacement, I just want the easiest fix to swap straight back in there. My car is an F reg S2 if that helps? Also, how to you get the old bulb out? Do you have to remove the plastic fascia over all the instruments and re-glue it from the front, or is there a way to remove the bulb holder from the rear of the dash. I had a go last night but couldn't seen to pull it out from the back. What a faff!
So I did eventually manage to get the bulb out today. The red part is still in the dash, but the lamp bit slid out of the back (after a while). Question is, where do I find a replacement which will fit back into the red lamp housing which is still in the dash? Or just a replacement bulb? I can't see any way of removing the red bit in the dash without taking off the front cover-panel, so I'd prefer not to replace the whole unit. The offending article is below. Also, needs to draw 5w in order for my alternator to work again!
Right, time for a quick update back on the original topic!
Finally got my replacement sender fitted this evening. I ordered this unit from eBay and it came with a new seal and lock ring.
After removing the old sender, I did a trial fitting and found a couple of issues.
1. The replacement is too long to fit in my tank due to baffles which I didn't realise were in there.
2. The plastic base on the new sender is much thinner than the original unit, so the new lock ring, seal, sender combo thickness isn't enough to provide a seal.
3. The replacement has two plastic 'locators' on the rear of the plastic base plate. These didn't fit into the inside diameter of the hole in my tank. Probably only 1mm in it, but I didn't want to crack the plastic by forcing it.
Solutions:
1. Took the float off the old unit (after checking it still floats in fuel) and cut/bent the new sender wire to fit the tank baffles etc.
2. Did a trial fitting using the old rubber seal + new rubber seal on each side of the sender to make a 'sender sandwich' and make up the lost thickness to provide a seal.
3. Filed off one of the two plastic locators on the rear (as they didn't locate into anything on my tank (they probably do on a Landrover to ensure the sender stays vertical during tightening, but not on a TVR...)
If you also take the locators off, you will want to angle the sender by about 45-90 degrees, so that once it's tightened (and turns with the lock ring) it sits vertically in the tank.
Old and new, as delivered:
After revision 1 (still too long to fit) using float from old unit:
After revision 2 (finally fitted):
From the side (as fitted):
I also used some non-setting fuel resistant gasket compound to try and help the seal work.
I'll update once I've been through a full tank of fuel to see how accurate it is now! Hope this is useful for someone. Now to fix the alternator lamp... ordered a 1.5W bulb and a 20 Ohm 4W rated resistor, so hopefully I can trick the alternator into thinking it's 5W.
Finally got my replacement sender fitted this evening. I ordered this unit from eBay and it came with a new seal and lock ring.
After removing the old sender, I did a trial fitting and found a couple of issues.
1. The replacement is too long to fit in my tank due to baffles which I didn't realise were in there.
2. The plastic base on the new sender is much thinner than the original unit, so the new lock ring, seal, sender combo thickness isn't enough to provide a seal.
3. The replacement has two plastic 'locators' on the rear of the plastic base plate. These didn't fit into the inside diameter of the hole in my tank. Probably only 1mm in it, but I didn't want to crack the plastic by forcing it.
Solutions:
1. Took the float off the old unit (after checking it still floats in fuel) and cut/bent the new sender wire to fit the tank baffles etc.
2. Did a trial fitting using the old rubber seal + new rubber seal on each side of the sender to make a 'sender sandwich' and make up the lost thickness to provide a seal.
3. Filed off one of the two plastic locators on the rear (as they didn't locate into anything on my tank (they probably do on a Landrover to ensure the sender stays vertical during tightening, but not on a TVR...)
If you also take the locators off, you will want to angle the sender by about 45-90 degrees, so that once it's tightened (and turns with the lock ring) it sits vertically in the tank.
Old and new, as delivered:
After revision 1 (still too long to fit) using float from old unit:
After revision 2 (finally fitted):
From the side (as fitted):
I also used some non-setting fuel resistant gasket compound to try and help the seal work.
I'll update once I've been through a full tank of fuel to see how accurate it is now! Hope this is useful for someone. Now to fix the alternator lamp... ordered a 1.5W bulb and a 20 Ohm 4W rated resistor, so hopefully I can trick the alternator into thinking it's 5W.
phillpot said:
No secrets here, what brand of "super goop" have you used?
I used Hylomar Universal Blue, which states it is fuel resistant... I'm yet to top the tank up and see how resistant it actually is.Oldred_V8S said:
There are plenty of places that will repair and refurbish a lot cheaper than buying a new one. I don't understand why some people immediately think buy new. Let's keep the small people in business, it would be a shame if they vanished.
I did end up taking it to llandaff recons in Cardiff for a re-furb, only for the chap to tell me that there was nothing wrong with it. Currently waiting for my replacement alternator lamp/resistor combo to turn up so I'll see whether that fixes the problem by this weekend.As a final follow-up on the alternator issue, I ordered a new alternator warning lamp of the variety that phillpot suggested on the assumption that they are around 1.5W standard, as that's what a couple of internet sites quoted them as. Also ordered a 20 Ohm 4W rated resistor and wired this up in series with the lamp. Fitted both, and the alternator is now charging again! As instructed by the TVR handbook, the charging only starts after the throttle is blipped, and the light goes out over about 2000 rpm in my case (probably due to the resistor and lamp combo i've used). I'll remember to pay a bit more attention to these lamps in future... Thanks for the advice all!
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