Diesel starvation ?

Help! My 1996 300 tdi defender has developed a severe lack of power. It is Ok for the first few hundred yards then gradually to nearly nothing. Going up hill means down the grears to about 3 MPH. Occasionally it is too much for 1st so I have to stop, wait for a while then carry on. It feels like fuel starvation so have checked fuel line. The sedimenter has previously been removed so fuel line (which looks quite new) goes straight up front. It is a fairly new filter and I have just fitted a new pump. Exactly the same. I have also blown the feed pipe from the pump back to the tank in case there is a filter in the tank that is blocked but that is clear. I have also tried it without the filler cap on the tank. When revving (which it does from idle) the smoke (initially black) then goes a whitish colour (unburnt fuel ?????) When revved, both the top air pipe and the short right angle air pipe to turbo go very hard so turbo is building up pressure and whistles as usual. When returning to idle it is very lumpy for a few seconds (as if diesel levels are building up again?) The valve on the manifold (EGR?) has been blanked off. I had the same symptoms about 3 weeks ago but it just cured itself????? Where now?

New lift pump next !!! Pull pipe see if its moving enough fuel into a jar ! Should pump a good squirt every stroke of the pump ! Cheap fix!!!!

Make sure you fit a DELPHI lift pump!!!

I have fitted a new pump.
Any other suggestions?
I was thinking (always dangerous)
Would these symptoms be caused by air starvation??

New here and unfamiliar with the 300tdi. Isn't it a common rail system that relies on very specific pressure and flow to operate the injectors?
If so I would assume there is a pressure drop, either at the one end of the rail (the pump) or the other where excess fuel returns to the fuel tank.
I assume there is a pressure valve that maintains a minimum pressure in the rail and returns the excess to the tank, which a pressure measurement can be taken.
Since for proper operation you need both adequate flow and pressure if one is mishing the engine will either run poorly or not run at all.
In this case I see in this diagram your problem may be back at the tank at the return circuit.

http://www.landroverexpedition.com/wp-content/uploads/300tdi_fuel_system_diagram.png

Quick Fix: Replacing 300Tdi leak-off pipes | Land Rover Expedition

zerogara said:

New here and unfamiliar with the 300tdi. Isn't it a common rail system that relies on very specific pressure and flow to operate the injectors?
If so I would assume there is a pressure drop, either at the one end of the rail (the pump) or the other where excess fuel returns to the fuel tank.
I assume there is a pressure valve that maintains a minimum pressure in the rail and returns the excess to the tank, which a pressure measurement can be taken.
Since for proper operation you need both adequate flow and pressure if one is mishing the engine will either run poorly or not run at all.
In this case I see in this diagram your problem may be back at the tank at the return circuit.

http://www.landroverexpedition.com/wp-content/uploads/300tdi_fuel_system_diagram.png

Quick Fix: Replacing 300Tdi leak-off pipes | Land Rover Expedition

Click to expand...

the 300tdi is not a common rail injection, it uses a mechanical injection pump

timbeauuk said:

I have fitted a new pump.
Any other suggestions?
I was thinking (always dangerous)
Would these symptoms be caused by air starvation??

Click to expand...

have you checked the turbo hoses? some times they come apart on the inside blocking the airway

Could be a cracked filter head letting air into the fuel line?

Or a union somewhere letting air in.?

You will have to wait till in stops and then see where there isn't pressure, lift pump should squirt fuel everywhere should be pressure at the bleed screw on the filter head. should be pressure feeding into the pump and then at the injectors.