Could be a number of things (some of them have already been mentioned):
Check all the intercooler hoses: Delaminating could be one problem, but check for splits etc.
When you drive it, can you here a hissing sound?? - air escaping??
Fuelling (lift pump): Unscrew the fuel filter and see if it is filled to the brim (engine off)
If not, it is a sign that your lift pump is not pumping the required amount of fuel... i.e. that it's gone weak.
Injector pump: You may have a split diagram in the top of the injector pump or it has been set to the wrong position
To check this, (with engine off) remove the four screws from the anode on the top of the injector pump.
Mark the position of the diagram with a marker pen so that you can put it back in the same place, and then remove it by gently pulling upwards and check for splits.
If it is ok, then.... it may be at its minimum setting.
The diaphragm and cone controls the ratio between boost pressure and associated fuel delivered. A small pin (which controls fuel) slides against the side of the cone. As the diaphragm is pushed down, the pin slides inwards against slope of the cone and so more fuel gets delivered.
As you look at the profile of the cone, it has different slopes depending on which angle faces the pin. So depending on its rotation, you can set which slope faces the pin, and so which ratio of fuel to boost pressure is delivered.
Its max setting is the one that would cause the pin to move the most. I.e. so that the largest is facing towards the front of the engine. It's up to whether to set it to max or not, but I put it somewhere close ish (say 30 degrees from max). If the diagram has been assembled correctly there will be a dimple of the metal plate which should face towards the rad on the max setting.
Can do a pic if needed.
Related to the above... Another possible cause.Following the same process as above, remove the rubber diagram from the injector pump, and have a look down the inside of the pump where the shaft on the diaphragm sits…
You should be able to see the tip of a sliding pin (on the rad side of the pump)…
This pin (called the guide pin) controls the fuel regulation on and off boost…
Basically when boost pressure is created, the diaphragm is pushed down, which allows the pin to move out, which in turn increases the fuel supply.
It's known for this pin to get seized, which means that you only have off boost fuel settings… and power is dramatically reduced as the engine is running to lean.
This either means a rebuild, or may be worth spraying copious amount of WD40 down the shaft, and try and free the pin if it is seized.
To test to see if the pin is moving…
Remove the diaphragm and clean the section under the rubber diagram, (i.e. the operating profile), removing any marks, grease etc….
Then, smear fresh grease over its full length (don’t need loads, just a thin layer) and replace the diaphragm and top cap.
Go for a quick drive ensuring you get the turbo to produce boost pressure (vehicle needs to be driven as boost pressure is only produced under load)
Then, remove the diaphragm again and…. If the pin is moving correctly there will a witness mark in the grease along the length of the shaft… if no mark, then you know that the guide/operating pin is not moving.
Throttle Cable:Another favorite... check the accelerator cable is adjusted correctly, as they have a habit of stretching or backing themselves off.
With the engine off, get someone to press the accelerator pedal to the floor, and check the lever on the injector pump gets to the 'maximum' stop, if not adjust as needed.
Boost Pipe: Check the pipe that runs from the actuator on the turbo to the anode on the injector pump - it may be that this split or blocked (disconnect and blow through with an airline)
Boost pressure of the Turbo and checking the actuator: Connect a Boost Gauge and go for a drive - try and find a longish hill and attack it flat out in 4th (or 3rd) and see what the maximum pressure is. It should be 1 bar or 15 psi (just over a bar which is 14.7psi) - if lower then adjust to suit. (1bar on a 300Tdi, 0.8 bar on a 200Tdi - though you can run 1 bar without a problem on a 200Tdi)
If pressures are lower than they should be, then you need to shorten the actuator until you reach the desired pressure.
However, even under lighter loads, with a boost gauge connected you should see pressure rises (though, unlike a petrol, you will never see a negative pressure).
Just to check everything isn’t seized though…
With a pair of molegrips attached to actuator arm (with engine off) you should be able to actuator arm towards the bulkhead. It will have quite a bit of resistance, but will show if the wastegate has seized, or a fault in the actuator.
If you prefer, you could remove the little ‘C’ clip that holds the actuator arm onto the waste gate and move them both independently.
Engine Timing: Does the engine struggle to start?? Or smoke when running.
To check....(engine off)
If you look on the front cover on the engine, you will see an inspection plate attached by three screws, remove this and you will see the pulley that drives the fuel injection pump.
If you look at this, you should see a timing hole. Turn the engine over with a bar (with a socket on the damper bolt) until this timing hole lines up with the timing hole in the timing cover behind the pulley (use of a torch helps) - when it does insert an 8mm or 10mm drill bit (plain end first) - if you gently try turning the engine over now, it should be locked.
Once this is locked, go underneath the Land Rover (with a torch) and look up through the hole in the flywheel housing at the flywheel. If the timing is correct you should see a cut out in the flywheel. If it not there, try just turning the engine slightly either way with the bar (still with fuel pump locked) and look to see if you can see it. If the timing is correct it will be there.
If not.... remove the drill bit from the fuel injector pump and get somebody to turn the engine over with the bar until you can see it, to see how far out/and what your looking for.
Read this guide for some pics etc:
http://www.difflock.com/servicing/300tdi-timingbelt/index.shtmlIntercooler: Get it leak checked or do it your self.
Easiest way is to bung one end, and pressurise the other (ideally between 1.5bar and 2bar) and then submerge in a tank of water - then look for bubbles.
Inlet Manifold: Make sure the gasket is ok and not leaking.
Fuel Lines: Check all the fuel lines for split, cracks, kinks etc etc.
Especially those on the feed side.
Might also be worth removing the pick up pipe out of the tank and checking the gauze (if fitted) is clean and the end of the pipe (and the whole pipe for that matter) is free from damage - also check the return is not blocked or damaged.
Fuel Cap: Remove this when the engine is running (or just after) do you get a hiss of air??? - if so, fuel tank vent or vented cap may be blocked.
Ian
