Wonkey fuel gauge/sender

[Gizmoman]

82 diesel 1.9 AAZ
Just a quick query as to why my fuel gauge has gone wacky.
A few months ago I replaced the tank and sender and everything was working fine. My old sender was a bit gunked up because I think the PO had fed some sealer into the tank (one of the reasons I replaced it).
The new sender never showed a completely full tank but other than that it seemed fairly accurate.

Yesterday I filled the tank and after starting the engine the gauge rose very slowly - like 10 minutes - and it never went over half full (the tank was as full as it could get). Today, on my first trip into town it never moved from zero, then later on another trip, it went back to the half-way mark but no further.

I should mention that I have had the dash cowling off (including the connector to the crusty foil) and possibly my connection is bad.

Any ideas would be appreciated,

Jim
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82 Vanagon Westy - AAZ 1.9 TD, HE200 Holset, WAIC, 27.75 dia tires, Electric power steering, 5-speed AAP w/.078 5th
Oversize spare carrier - stock location (no longer for sale).

[davevickery]

Until someone with more experience posts, I will add what I read about it. I believe the sender works off of resistance and the higher the resistance, the lower the gauge reads. So if you have a lousy connection somewhere the gauge stays on empty or reads low. I removed the plug from my sender and cleaned it a little bit and put it back and that seemed to help. But it is easy to get to on a syncro. Someone suggested adding a local ground wire to the plug but I didn't want to cut up any wiring so I just cleaned it up and put it back. Could also be the connection at the cluster or in the foil.

[AZ Landshaper]

Theres a resistor of some sort back behind the gauge and cluster that reduces voltage. Three pronged looking thing. You should be testing this dohicky.

Obviously I know enough to be dangerous. Take my advice w a grain of salt.


Look it up. Its there.
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Support Small Business.

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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[Gizmoman]

Thanks for the tips.
Started working again so I'm not gonna touch it. The foil is like something you'd find in an Egyptian sarcophagus so until I can afford the available upgrades to that I'll just hold my breath.
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82 Vanagon Westy - AAZ 1.9 TD, HE200 Holset, WAIC, 27.75 dia tires, Electric power steering, 5-speed AAP w/.078 5th
Oversize spare carrier - stock location (no longer for sale).

[campism]

My gas gauge has been working fine for the eleven years we've owned the van but recently became intermittent. While heading out to a trailhead last week I happened to be glancing at the gauge when it plunged from halfway to empty. Upon restart after picking up my buddy it worked again but quit again later and has started and stopped a couple of times since. Guess I get to do some troubleshooting.
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'87 Westy in Wolfram Grey Metallic

[Jon_slider]

if replacing the sender and replacing the gauge do not work, that leaves the foil as the culprit

my 85 Westy w over 250k miles.. foil is bad to the temp gauge, it reads very low, all the time. It used to be intermittent, work, no work.. now, always no work

replacing the temp sender, Tstat, and gauge did not work

the shop installed one of their working instrument clusters, and my gauge works with it.. that convinced me its the foil.

My gas gauge still works, if it didn't, I would reset the trip meter at each fill, and refill at 150miles..
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My Soapboxes: Inflation; Handling; Gearing; Decoupling; Swepco

[Gizmoman]

I've had some luck checking out the foil with a magnifying glass and gingerly soldering tiny jumpers to bridge questionable traces.

The folded area where the connector slides over is looking pretty rough though, and I believe this is where the issue may be. With a lot of patience I could re-make this area but it would be a real pain in the neck.
Best bet is to simply replace it with one of the offering from Go Westy or another vendor.
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82 Vanagon Westy - AAZ 1.9 TD, HE200 Holset, WAIC, 27.75 dia tires, Electric power steering, 5-speed AAP w/.078 5th
Oversize spare carrier - stock location (no longer for sale).

[AZ Landshaper]

Nothing to do with this part?

http://www.van-cafe.com/home/van/page_104_154/voltage-stabilizer-see-description.html

Guessing if your temp gauge is ok then prob not. Just a thought.
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Support Small Business.

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85 Weekender w/ EJ22
Previously
64, 71, 72, 73, 76, 81, 84, 85 & 87 Campmobiles and Westfalias
and a 67 bug.

[Gizmoman]

Temp gauge is fine but thanks.
It's working for now so I'm not going to mess with it.
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82 Vanagon Westy - AAZ 1.9 TD, HE200 Holset, WAIC, 27.75 dia tires, Electric power steering, 5-speed AAP w/.078 5th
Oversize spare carrier - stock location (no longer for sale).

[Achilles3588]

Gonna resurrect this old thread as I'm having similar issues as the OP had.
'91 Diesel Syncro Doka 1.6JX to 1.9 AFN swap

I replaced the sender at the engine swap. Cleaned out the tank and replaced all the hoses with a kit from Brickwerks; also replaced the sender. Made very sure to put everything oriented the way it came out and checked against various resources to ensure this was being done correctly.

The gauge only goes to about 5/8 when completely full. It zeroes out well before the tank is completely empty, probably 9 or 10 gallons as I'm only able to put 8 or 9 in on filling up when the gauge hits the reserve mark.

- Voltage regulator is good, the temp indicator works perfectly.
- Have a good ground wire at the sender plug
- jumper across the sender wires causes the gauge to peg high (reads above full) so I have to believe the gauge is good.
- Have the rig on jackstands at the moment, with about 1 or 2 gallons remaining in the tank. Resistance across the sender leads = 268.6 ohm. This seems consistent with the Bentley table for VW 1301: seen here.
- There is a ground connection for the sender which grounds out on the exterior of the sender mounting plate. Checked the continuity of this connection point to the sender lead inside the plug on the sender plate. This shows a good connection virtually no resistance.

Any further help is appreciated.
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Larry V.~
'91 Syncro Doka 1.9L TDI 'AFN'

[valvecovergasket]

i know this is maybe covering ground that you may have already covered bits and pieces of in your testing - but i think it would be worth investing in a cheap decade box from amazon

then sweeping the gauge via the decade box using the wiring down at the tank.

it seems likely your issue is at the gauge, but its a nice double/triple check
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MegaSquirt resource - SpitfireEFI.com

gone, but not forgotten: '83 tdi westy - swap thread

[Achilles3588]

[valvecovergasket]

if i read right though you confirmed the sender resistance its current reading, which matches, and checked the gauge pegging when it was shorted - id say theres worthwhile testing to be done with the decade box still.
i may have misread though! if you already did the intermediate positions/levels with the new sender before installing.
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MegaSquirt resource - SpitfireEFI.com

gone, but not forgotten: '83 tdi westy - swap thread

[WiboBusMan]

I had this with my '84 westy... Just to be clear, my gauge was mostly reading low, and not reliably so, jumping around at times.
Did the fuel tank pull, sender replace, wiring check from the t14 connector to the sender...
Turned out to be very slight oxidation at the gauge connection (the small brass nuts securing the gauge to the display plate).
In case you don't know, the foil circuit is very delicate, so extra care is in order.
Disassemble, clean the foil connection points with a pencil eraser, clean the contact surface of the brass nuts similarly, and if you are lucky, reassemble and voilà, no more wonkyness...
W
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Science has sacrificed Truth on the altar of its narrative.

[Achilles3588]

[tarandusVDub]

Hi all, my gauge was working fine until I took my new-to-me syncro doka for some mudding, then it stopped. It's pegged over full, so from this helpful thread I think the ground must be bad for the sender?

Thoughts on whether its better to trace the ground wire and fix that at the chassis (or replace ground wire), or if I can just tap the brown ground wire at the sender in the wheel well and do a new ground and call it good?

I want to fix properly but one is way easier/faster than the other...
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1990 Syncro 16" DoppleKabine 2.1 DJ 112i
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Sold: 1972 Bay Campmobile; 1984 Westy, base model, 2WD.

[Achilles3588]

[tarandusVDub]