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Gas gauge problems

1K views 8 replies 4 participants last post by  pnt4u2 
#1 ·
My gas gauge is, to say the least, disappointing. It worked - kinda - when it was new, but now, nothing. The gauge appears to check out using the installation sheet diagnosis instructions so that leaves the sending unit.

When I check the sending unit ohm output, it reads 7.2. With a tank that's 3/4's full, it probably should read in the 130 ohm range. This sending unit is a 10 (empty) to 180 (full tank) ohm unit. Before you ask, grounds and connections are solid. My question is - anyone here have a problem with VDO tank senders? They aren't particularly expensive at about $26+ shipping from Summit, but - dang I'm getting tired of replacing brand new parts that don't work as advertised. I can make enough of my own expensive screw ups and suffer the dollar consequences, but ....... :pain:

Dave W
 
#2 ·
Irelands child said:
....My question is - anyone here have a problem with VDO tank senders?..... :pain:
Sounds like a ground....just kidding.

I've had problems with aftermarket gas gauge senders too, and not just VDO. Seems like maybe 1 in 4 doesn't last a year. On the bright side, it seems like 3 out of 4 are just fine and last for years without any problems.

Good luck... :thumbup:
 
#3 ·
VDO no!

Had problems w/my VDO guage a while back. Dropped tank and found condensation in tank causing rust on sending unit and the unit was in 90 degrees out. It should have been installed to operate left to right not forward to back. That allowed fuel to slosh float and unit around while driving. I changed out unit with a unit from Summit, installed unit left to right and haven't had a problem. I do use HEAT fuel additive from time to time to "dry up" my fuel. Just in case. Hope that helps.
 
#4 ·
Guys - anything helps. I just ordered a replacement from Summit.

Now as far as condensation - maybe, but probably not since it has never been much good for giving me a real reading. As far as orientation - there is only on way it can go in this '32 tank as it would interfere with the pick up.

Joe - I too would have said ground - except the reading was ----7.2 ohms hooked straight to the battery neg terminal which is about 18" away and in the trunk of the car or to the normal ground:nono: :D :D

Dave W
 
#5 ·
Well while waiting for Wednesday's delivery of my gas tank sending unit, I decided to see why my tach was 'lazy'. It looks like MSD and VDO can't get their acts together. MSD says I need an adapter as did the original instructions I received from VDO. WRONG!!! That $50 gadget just ain't needed and the latest VDO instructions I pulled off the web also say that. The VDO dip switch settings were wrong as well. With my MSD 6A box, my settings turned out to be OFF-OFF-OFF. It took about an hour of fussin, but 'ain't it fun'. Of course that adapter is so buried in the dash that unless I pull the cowl cover, it will not see the light of day. :D

Dave W
 
#6 ·
Interesting repair to say the least. The amount of corrosion on the gas sender would have to be seen to believe. I know that I got one tank of less then stellar gas (Hess 93 octane - smelled real strange and the car ran crappy) but since then it has had only three buck plus/gallon Mobil. The amount of ethanol currently in the gas is my guess as to some of my problem as that corrosion appearance is not what I would expect from water. Makes me wonder what my carb innards will look like in a year or so.

The new sending unit works like a charm, the old one after being cleaned will now be a spare as it too works just fine. Sure am glad that I made a tank access hatch when I built the car :D

Dave W
 
#8 ·
mud.man.rj said:
Glad you got it figured ouy elect is a time consumer isn't it. :p
I don't have a problem when I make a mistake, but this was material that was new and didn't 'hack it'.

Oh well, the tach now works, the gas gauge works right and so do all the rest of them :thumbup: :thumbup: I might even go for a ride tomorrow!!! :D

Dave W
 
#9 ·
Rust source?

Just an after thought. I found after I dropped my tank for the VDO sending unit, I also had some aliens in my tank too. I cleaned and coated my tank while I had it out and again not a problem since. Ethynol, water or whatever made the rust. It's gone for now. I am glad you found the problem.
Happy cruisin'
 
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