jcb 3c mk11 excesive fuel consumption HELP!!!!

[engineeringblue]

Hi all , so you have helped me in the past so I thought I could bend your ears a little more.
My old 3c mk2 is running well and I have replaced a few things and serviced it including new hydro oil etc , apart from the usual leaks I noticed that iam using it a lot more lately on this project and I put 25 litres of fuel in her the other day and it only lasted me about 3 days , not full days of work I might add.
I noticed one thing when i top her up i hear the fuel venting through the bulkhead where the hydro oil is housed ??? Is the fuel tank inside the hydro oil or have they just used one of the vents which comes through the hydro oil tank , there is a couple of vents on the bulkhead below the windscreen which vent pressure when i turn her off and the hydro oil stops circulating . Unless this is a coincidence when i topped up the fuel i was listening to the hydro oil pressure realising through the vent ???
Anyhow there is no leaks oil fuel and apart from a little easy start when she is low on fuel or I stall it under load she runs well.

HELP PLEASE
DARREN

[charlie2]

fuel tank breather is as you say under windscreen the fuel tank is the bulkhead, hydraulic tank is chassis sides and front crossmember check the engine oil level isnt rising as the lift pump can leak into sump, and injection pump could leak through front seal into timing cover and drain into sump. 25ltrs isnt a lot for three part days i would think.

[essexpete]

It should not need easy start, especially at ti's time of year. 25l over 3 days sounds next to nothing to me. Just make sure, as said above, there is not diesel getting into the oil.

[engineeringblue]

Thanks for your info
I will top it back up with fuel and check the levels. I do check them quite regularly. It does my head in every now and then if ut stalls under load it won't start unless I use the easy start . , apart from that the only other thing I'd like to fix is the temp sender . All the electrics work on the dash but that . The cable from the thermostat has broken years ago by the looks
Maybe I should strip down and clean the lift pump to solve the restart problems eh ???

[MrF]

If you need easystart when its low on fuel it might be worth checking the fuel filters first because that does imply it needs a head of fuel pressure to pump. Not forgetting the mesh filter under the cap of the lift pump itself, and the one in the bottom of the tank pickup if it still has it. Then new elements all round to be sure.
As for 25l over 3 days, Im with the others, if its been working as above, Its a 3.8L non turbo engine designed in pre-history to go in a tractor, and not known or built for economy.

[essexpete]

I had misunderstood. Does it stall easily under load from hydraulics or moving off? If it won't start when hot then I guess you have a fuelling issue. Probably best to go through the whole fuel system pre injector pump. I had a Perkins 6.354 in a Hymac that would not start when hot. Sound a dodgy thing to do but if I tipped some water over the injector pump it would start. I assume there was part of the pump worn and the tolerances went out even more when hot.

[Matchless?58]

My 3c11 goes through 25l in no time at all so it sounds about right to me . You have to balance out the enormous amount of work you can get through in a short time with these machines especially if it's straight digging , against the cost of the fuel . It actually works out to be fairly cost effective in the end . Don't think you have much to worry about .
Re the starting issue after stalling my moneys on a blockage at the fuel tank end especially as you can hear air being sucked in through the breather when you stop . I had a similar issue on mine but it would run until turned off then not restart . I cleaned out the fuel tank then put in an extra inline filter before the lift pump . You might notice it happens more when the machine travels over rough ground and is rocking about when working hard . This stirs all the crap up in the bottom of the tank which then blocks up the fuel feed . I would be interested to know if you solve this issue .

[engineeringblue]

Hymmmm I have a few things to go on now guys.
Sounds like you all have the idea . I have done so much work with the machine now as we have used it to build a complete house including excavation of an indoor swimming pool, all the footings and also I fabricated a 4m crane jib to fit the front bucket so I could lift 25 attic trusses onto the roof without the hiring of a telehandler .
So she has worked really well . I will give her some love this week and clean the fuel system out I think . I will post my findings soon as iam done .
Cheers guys

[engineeringblue]

So guys , i cleaned the lift pump which was a little dirty , and ive kept the fuel tank a quarter full and she has started every time now , she had just dug a swimming pool for me measuring 1.5m x 9m x 4m in one day . really pleased with her.
thanks for the help again guys