Wont go up the revs, goes lumpy.

Guys,
300tdi.
Changed the fuel filter and lift pump bled it until fuel comes out. Got it running but won't hold high revs. Any ideas?

Throttle cable adjustment?
First thing to check..

getting air in somewhere? re check filter and disturbed fittings.

Thudmaguffin said:

Guys,
300tdi.
Changed the fuel filter and lift pump bled it until fuel comes out. Got it running but won't hold high revs. Any ideas?

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If we assume for now anyway it is not a injection pump issue then I have to say it sounds like fuel starvation.

Over the years of working on Landy's I have seen this 3-4 times, last time was in my own 300tdi and it was a piece of silicone stuck in the union at the top of the pickup pipe!

Start the landy, then crack off and unscrew a few turns the bleed screw on the filter housing, you want to be seeing a flow of diesel shooting out across the engine bay, really quite serious flow, if you get a dribble or a measly little fountain an inch or two high then you have an issue - start working back down the fuel line. If flow is good then move further along the system you could go directly to the return line on the injection pump and have a look there you are looking for lots of volume. A lack of good volume and you know this is a starvation issue.

Is your tank in good fettle? What pickup pipe do you have, standard pipe or mesh tip? Fuel good? Do you run a lot of fuel through your landy? Does it stand a lot, did it get water in it?

If fuel lines, leak off pipes are all ok and fuel coming up then I would look at the little pipes from the turbo to the pump, if they are ok then look at the valve that allows more fuel when revs are up, this has been known to stick due to corrosion. it's easy to check but be sure to mark the position of the bits you take out. I had one that was stuck and a quick clean and some lubricant sorted it.
I'm sure there will be many more suggestions of what it may be for you to check, just a matter of elimination really, could even be head gasket that's causing the problem but then you would get smoke with the lumpyness.

landowner said:

If fuel lines, leak off pipes are all ok and fuel coming up then I would look at the little pipes from the turbo to the pump, if they are ok then look at the valve that allows more fuel when revs are up, this has been known to stick due to corrosion. it's easy to check but be sure to mark the position of the bits you take out. I had one that was stuck and a quick clean and some lubricant sorted it.
I'm sure there will be many more suggestions of what it may be for you to check, just a matter of elimination really, could even be head gasket that's causing the problem but then you would get smoke with the lumpyness.

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I see where you are coming from but this isn't turbo related, engine would pull the full revs it could naturally aspirated and hold them there, albeit less than boost fuel max revs, although, at no load WOT it should actually reach the 4800rpm.

discomania said:

I see where you are coming from but this isn't turbo related, engine would pull the full revs it could naturally aspirated and hold them there, albeit less than boost fuel max revs, although, at no load WOT it should actually reach the 4800rpm.

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Agreed, could be head gasket then, I had one like that, changed injector pump, injectors etc for known good ones but ended up head gasket even though no other signs.