Kangaroo diesel

[Rorie]

Disco 200tdi

When I accelerate above about 2,000 RPM, the engine looses power. If I keep my foot steady to maintain constant RPM, I get a kind of kangaroo effect (though not regular jumping).

This is making life very difficult and almost undrivable when I need to pull off from junctions etc.

Sounds like a fuel supply issue to me, so I checked and there are no fuel leaks from the tank to the engine.
Any other suggestions as to what it could be?

 

[wammers]

Fuel filter blocked, lift pump duff.

 

[jamesmartin]

as said lift pump is common as are sedimenter and sender unit in the tank ,up to the lift pump the system is in suction so leaks arent allways evident but air can enter

 

[Rorie]

Ok great. I have noticed that I do not have a sedimentary though... Is it normal for ppl to remove these?

What's the best way to isolate and check each of the possible causes? I know a replacement sender unit isn't cheap!

 

[Rorie]

That said, the manual priming lever on the lift pump has never worked (though also never had this issue). It just sits there flapping around. Perhaps an early indication of failure?

 

[jamesmartin]

Ok great. I have noticed that I do not have a sedimentary though... Is it normal for ppl to remove these?

What's the best way to isolate and check each of the possible causes? I know a replacement sender unit isn't cheap!

it is when they become blocked or corrode so not air tight,you can look under the plate in the boot floor corroded pipes on sender unit is a good sign they may well have a leak,priming lever wont work if cam is holding the pump diaphragm in the raised position,but then many dont work anyhow,which is no problem as long as cam operates pump, a clear piece of plastic between filter outlet and front banjo bolt on injection pump will show air if there is some or undoing front banjo bolt and getting someone to crank engine with solenoid wire off and seeing if you can see clean pulses of fuel or whether there seems to be air

 

[Rorie]

I have had a look around the disco and i can see a couple different joints in the fuel pipe. I am thinking that if i replace the sender unit, its worth my while changing the fuel pipe too. But i'm struggling to work out the size - i have read on the forum various statements between 8mm and 10mm ID.
Is the return a smaller dia?
Most fuel pipe i find is thick rubber tubing, rather than the thin plastic stuff on my disco just now. what am i best using?

Thanks

 

[Disco1BFG]

I have had a look around the disco and i can see a couple different joints in the fuel pipe. I am thinking that if i replace the sender unit, its worth my while changing the fuel pipe too. But i'm struggling to work out the size - i have read on the forum various statements between 8mm and 10mm ID.
Is the return a smaller dia?
Most fuel pipe i find is thick rubber tubing, rather than the thin plastic stuff on my disco just now. what am i best using?

Thanks

IMHO, I doubt the type of fuel pipe will matter - but the thicker stuff will take a bit more routing and securing to the chassis than using original size/type stuff, which will ( obviously) just fit into the original clips.

Again IMHO put the sedimenter back ! its there for a reason - mainly to keep water out of the IP, but also to keep cr*p out of the rest of the system too. This may get rid of some of the extra joints too...

Agree that the usual suspects for your OP are lift pump and fuel filter. use a good quality lift pump if you can get one - delphi / bearmach.

 

[Rorie]

Ok so starting at the tank, the sender unit lines are rusty as heck and the plastic section is all cracked. The unit is marked with ESR1223, so i am going to order up a new one. I am trying to see on the photo what connectors come with it and how i hook this up to the pipework. Any ideas?

I am keen to replace the fuel line and return though - there are a couple breaks in the pipe bridged by thicker pipe (ID matching original OD) and jubilee clips, so i don't think they can be trusted. I am still struggling to find the exact spec / size of pipe i need to get though. Any suggestions? Most of the original pipe clips are gone, so i am not concerned about that aspect.

 

[jamesmartin]

union and olive are nrc9770 and nrc9771, 8mm id for the fuel hose

 

[Rorie]

Thanks. I assume thats all i need to hook my hose up to the sender unit then?

Is the return fuel pipe the same size as the feed? I think i measured them at one stage and found them to be different?

 

[jamesmartin]

yes same size as far as i remember, it all you need if using original male fittings on original hoses

 

[Rorie]

Hmm, the originals are rusted to fook! Is it acceptable to push fuel pipe onto the sender unit and then use jubilee clips? Or do i need to buy new fuel lines to the sender unit (NTC7335). If i buy this (expensive!) it will only go to the sender unit...which doesnt exist.

Ideally i'd run new line straight up to the sender unit, so i just need to work out how to connect it up...

 

[jamesmartin]

Hmm, the originals are rusted to fook! Is it acceptable to push fuel pipe onto the sender unit and then use jubilee clips? Or do i need to buy new fuel lines to the sender unit (NTC7335). If i buy this (expensive!) it will only go to the sender unit...which doesnt exist.

Ideally i'd run new line straight up to the sender unit, so i just need to work out how to connect it up...

yes it is but use good quality hose clips, ive done it a few times
you could just buy a length of hose and run striaght to lift pump and back again using hose clips and fuel quality rubber hose

 

[Rorie]

great thank you for the help!

Final question (honest!); does it matter what kind of hose i use? I.e. braided or hard plastic. I guess the hard plastic is easier to get a good compression clip onto, but the braided would be more robust?

 

[jamesmartin]

something like this is the easiest
https://www.google.co.uk/url?sa=t&r...-p.asp&usg=AFQjCNHRKa5zDToCWlEbllzzYbmbFdOYoQ

 

[Rorie]

Ok thanks - i was looking at similar on flee bay.

Much appreciated! Hopefully this will solve my issue