Discussion in ''How To' & 'Handy Hints'' started by ttmck, Mar 18, 2007.
Ask them to confirm how deep you can cut also! Dont need extra holes in the tank lid!
Wish I'd seen this thread a couple of hours ago......It's taken that long for me to work out that you can't remove the firewall panel without dropping the engine, no matter how much you push,pry and swear !! Thanks Tom - great post. Cheers, Mark
Yes you can but getting it back in you need to lower the engine ..........4 bolts and a jack
I found this, the easiest way to loosen & re-tighten the sender unit. Use two hands
New senders float position check first
A little tip when fitted new senders , look at the orginal float and take note which was round it is .Now look at the new sender unit if the float is not the same way unclip the float and reverse it , Just because its new does not mean that its ok to put straight into the tank . its a bit like measure twice cut once ! Guess who got caught on this today , i must have fitted dozens and must have got lucky previously .
Also if you have a multimeter put it on the ohms scale take some readings to what the new sender is showing i believe prevoiusly posted was 10 ohms full and 73 ohms empty this should provide accurate levels , quick check to see if the gauge is ok just earth out the brown wire the one or the one that was originally on the terminal that is insulated with a white block on top of the sender picture is above and this one has two brown wires which not the norm. it should go to full very quickly . also connect your new gauge up and test it out of the tank once your ohms readings have been checked to adjust bend the tangs with pointy nose pliers .
It will go if you are suitably persistant
Just visited BCF today at Mt Barker, fuel sender ordered via Bus stop! All ready to jigsaw Karl!
My FUEL SENDER SAGA.
On the first fill-up on the way to the Easter Bus Stop the fuel gauge on Schmetterling started reading over full. The needle was right over way past full. That was 6 months ago and careful recording of odometer readings and kilometres travelled has avoided all but 2 occasions of running out of fuel. First was at home and the second was at a place that I was driven to and from the petrol station so there was minimum pain. Anyway, time to fix it!
Schmetterling is a 1979 Bay so the fuel monitoring system has 3 basic components. A fuel sender in the tank, a fuel gauge in the instrument cluster and a voltage regulator mounted behind the fuel gauge. The fuel sender sends a variable resistance to operate the gauge ranging from 73 ohms for empty to 10 ohms at full. My logic was that if the gauge is reading over full then there must be a fuel sender failure. i.e. the resistance was less than 10 ohm.
There are 2 basic ways to change a fuel sender in a late Bay.
Remove the engine, remove the fuel tank, change the sender and put it all back.
Cut a hole in the rear floor to access the sender, change the sender, and patch up the hole. (It has been suggested that the tank can be removed without pulling the motor BUT my experience is that it is more challenging than dropping the engine out.)
My spares Kombi has had the cut and patch done so I had a guide as to where I should attack the floor.
1/ Angle grinder = heat and sparks + petrol fumes = bang. Reject.
2/ Tin snips OK but hard work.
3/ Jig Saw. OK as long as the blade does not punch a hole thru the tank!
Step 1: Mark the cut area. See the pic for dimensions. Note that the hole is not directly above the sender but it works well for sender removal.
Step 2: Drill a small hole and check the distance to the tank with a piece of wire. Check the clearance against the length of the blade. Mine was about 63 mm. All OK.
Step 3: Drill some more holes so that I can get the Jig Saw started. Cut the hole and vacuum up the metal swarf. Not good in the fuel or the engine!
Step4: Remove the Sender. Take off the connections. Don’t lose them in the dark hole! With a drift rotate the sender ACW until it is free. Negotiate it out of the tank.
Step 5: Install a ‘new’ sender. NOTE. Take care not to bend the float arm or the ‘ears’ on the sender otherwise the tank readings will not be correct. Note 2. Make sure the seal is installed. With a drift rotate the sender ACW until it is secure. Re-attach wires. Earth to Earth and sender wire to the insulated terminal on the sender.
ALL GOOD? Test to see if it works. Switch on the ignition and the gauge should read the fuel level. OK?
Step 6: Patch the hole. I had the patch from my wrecker so it was easy but no drama. You will need a bit of metal bigger than the hole. An old scrap of VW floor would be good but no rocket science to find something that would do. Cut to size, seal and secure. I used some door seal around the edge and 2 bits of soft rubber to fill the floor grooves. Pop rivets were my choice but self-tappers would do. Pops are nice and flat and smooth.
For my job after I connected the sender the gauge still showed over full! Bugger!!
Checked the old sender with a multi meter and it was pushing out 10 to 73 ohms as required so the sender was not the problem.
Pulled of the sender wire from the back of the sender. Fiddly but do-able. Checked the resistance at the fuel gauge end of the sender wire with the multi meter and it was only 5 ohms. Too low!
Must be a problem with the wire run from the sender to the gauge. The wire runs from the insulated connector on the sender thru the tank area floor on the driver side. If you have a look underneath you will see it coming thru the floor and disappearing into the main wiring loom that runs to the front of the car. I connected a wire from the sender to the gauge to see if it worked and all was good. Cut the wire at the floor and ran a new wire from the sender connector thru the floor and connected it to the original wire. (Another fiddly process but if you poke a wire thru the hole from underneath you can hook it with another wire from the tank sender cut-out.) Checked and all good so the failure was in the run inside the fuel tank area. Cleaned up the connections packed up.
Will monitor the fuel reading when I fill up to ensure it is reading accurately. Job done!
Luckily I had a spare sender so did not purchase a new sender. And now I also have an access hole if the sender fails. Kombi fun!
Nicely documented Al ! I found that stainless steel jigsaw blades are a lot shorter than the others & used them......easily cleared the fuel tank.
Nice one Al
Stumbled on this old post; already had the hole so handed over 10 bucks to our local BCF for a 100 mm inspection hatch and it works great.
I never ran out of fuel untill I replaced my broken sender
the 100mm inspection hole doodad looks the goods...
As long as you seal properly. The cab floor is not flat metal.
I used pinchweld extrusion from Clark Rubber around the edge of the hole which makes for a flat surface for the inspection hatch to sit on and seals the gap.
Hi all, I too have a non working fuel gauge. No back n forth, no showing over full, just absoloutly nothing. No movement at all. I put a test light on the back of the gauge at the voltage reg connection and the sender wire connection and the test light slowly went dark, then light, dark, light etc. Put a multi meter on and it showed fluctuating readings. Is this normal if the sender is buggered? Or does it indicate a different problem?
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