I may have posted this way back in 2016 - but I have (unfortunately, several times) managed to successfully take out the sender on mine with no access hole, or engine drop. On a type 4, remove the carbs etc from the top of the engine, and you can just (with a bit of bending and swearing) get the firewall out. You can then carefully get to the sender, and with some rotation and moving it along the top of the tank, feed it out (with the arm type sender unit, at least)
I also have done this. You can even get the entire tank out. Getting the panel back on was a pain though.
I cut a hole. One screw on the firewall refused to move. Rather than faff about drilling it and using easy outs...... I cut a hole. If I take the engine out at some point, I'll remove the screw. I also didn't want to take my interior out which is sitting on carpet so..... I cut that too! In the end, I'm glad I cut the hole because the sender wasn't shifting without some "persuasion". I could also see what I was doing properly. I drilled a 12mm hole which was just enough to get the ends of a brand new pair of tin snips in. This seemed like the safest option. There wasn't really any petrol smell so I'm taking that as a good sign that my breather hoses are probably OK. Once I had a hole, I tested the sender cable by connecting a male spade connector and running a cable down the centre of the van to the sender. Then I could test continuity between this temporary cable and the sender cable at the sender end. In the dashboard, the sender was brown with a black stripe, at the sender end, it was a thicker, only brown cable so there must be a join somewhere. The cable was fine so it can only have been the sender. I've now replaced this and the needle now lifts on the gauge with ignition on. I can't remember completely, but when the gauge was working I thought I had about quarter of a tank. The new sender sent the needle just to the left hand side white line of the reserve. I've then put 5L of fuel in from a jerry can and the needle shifted another couple off mm into the reserve. I've seen a couple of comments here about calibrating the sender. I'd be interested to hear if anyone has actually done this and the methods they used. I'm thinking if I put 28L in I should have half a tank. If the guage then shows half a tank I suppose it's OK? The trouble is, I don't know exactly how much is in the tank now. I could then fill up and check the gauge shows full? Anyway, bit of a ramble but I wondered if you might like to see some pics?!
Modern aftermarket senders have poor calibration compared with even 14 years ago. Costs have been cut. Mine shows the start of the red reserve at half a tank full... The sender wire is joined externally in the upper part of the right hand rear wheel arch, exposed to the elements.. Mine reads over max for about 10 miles when full..
Similar experience to Mike’s, I had to bend the sender wiper stops a bit to get it to match the OE spec range which was something like 10-70ohms. Because the float and wiper move in an arc it’s not linear, so the windings should be spaced accordingly to compensate. My gauge also went pop shortly after so I ended up getting a marine multi gauge (to add oil pressure and temp combined) and a gauge-matching gizmo, and did my best to calibrate that, but that’s another story.
I also found the current replacements useless - again, I may have posted this already; but in the end I fitted a modern replacement (cannibalized into the original sender's mounting) and calibrated with a fuel gauge wizard. This also allowed me to install an orange LED to warn of low fuel for added bling. https://spiyda.com/fuel-gauge-wizard-mk3.html
Whereas I just slapped a replacement in (silva??) and it works perfectly. It's usually resistance from bad connection, bad voltage stabilizer thing and though I agree the accuracy between full and empty is laughable, I've been right down almost to the bottom of reserve and brimmed it to find I'd had about 3-4l left. It's good to know what that reserve really means - on mine despite empty and full being spot on, when I get to reserve I've got 2-3 gallons left, it's a healthy "reserve"! Full.
I used the same gizmo to match my sender to a new gauge. I actually PM’d a write up I did a few years back to G-Ram last night. My old gauge kept shorting out internally due to broken insulators on the connectors and eventually blew (it also didn’t come with a stabiliser and wouldn’t work with one when I tried). The replacement sender ‘worked’ but wasn’t giving the full range of resistance values. I think I tweaked the original one into line and put it back in from memory. https://r.tapatalk.com/shareLink?sh...r-market-fuel-gauge-fix)..61370/&share_type=t
