The Classic Machinery Network

Hi everyone !

I've been on the forums for a few months now and picked up some great information already , already downloaded all the manuals which are a great help

I've recently been getting an old 3CIII (1979) back up and running after it stood for over 6 years with the fuel filler cap off !

I ended up with a lot of sludge/rust in the fuel tank which kept filling the sedimenter and blocking the filter before stalling the engine. Eventually after several half hearted attempts to resolve things I took the fuel system apart (again) cleaned everything again and also removed the large 'bung' from the bottom of the tank (jacked her up on the legs so the bung was at the lowest point) and ran about 5 litres of diesel through again and again until it ran clean(ish).

After this I was thinking of following some advice I'd seen on CM somewhere about making a new fuel outlet higher than the original to stop the remaining sludge coming out, but in the end had a brainwave when I realised a standard 20mm plastic water pipe could be jammed firmly into the top of the tank bung (my gauze element had already fallen apart). This plastic pipe now extends the lowest point of the tank up by about 20mm which means I don't feed the last dregs of fuel/gunge down the fuel lines , obviously I run out now before the gauge says emtpy but it was a free fix !

Now I can use the machine on gradients without clogging the filters/pump and cutting out

Hope this helps someone else with similar problems sometime.

JC

Did you find access to the bung difficult?

No its easily accessible from straight underneath. I removed the fuel line first (small spanner) and then used a very large socket with an extension bar and ratchet to undo the bung. It did require the use of a long scaffold pole to 'crack' the bung and get it moving though, it was done up pretty tight, there is no way you can get a spanner onto it up the under the tank and even if you could you'd never be able to exert enough force to undo the nut

Another bit of info related to the fuel tank just in case it helps anyone....

The tank sender is on top of the tank directly in the centre, you have to remove the dashboard on a 3C Mk3 to be able to see it. There is a single male spade connector sticking out of the centre of the tank/bulkhead which is the sender -12v wire

Had to do the same thing on my 3c111 so me time ago. Took the bung out and washed the tank out with parafin.
Didnt need to put in the plastic tube though. Good to learn the whereabouts of the tank sender.

Wow!

I've just been wondering about rewiring my fuel gauge and thought I'd check here for info. The sender location is an excellent start, many thanks!

I realise this is an old thread, but does anyone know the actual wiring required for the fuel gauge? Some fool (before I bought the 3c111) decided to rip out ALL ancillary wiring!!!!!!

Having no idea when I'm about to run out of fuel is a bit tedious to say the least, shortly followed by not knowing how hot the engine is!

Any help would be much appreciated. Cheers, Pete.

Hiya, fuel gauge wiring as follows. The Sender is earthed through the tank if it just has one terminal one it. (Thats factory installed)
A green wire with a black tracer would route from the fuel gauge sender to the "sender" terminal on the fuel gauge.

At the fuel gauge, the two other terminal are earth, and positive feed. The positive feed would have been a green wire taken from the left hand fuse box. Fuse number one (5 amp)

Hope that helps. Cheers Mark

Oops,
just re read your post.

For the temp gauge, use the same green wire that's feeding the fuel gauge from fuse one.( Just piggy back off either gauge to the other), Earth obviously aswell. The temp sender wire would have been blue with a green tracer.