Land Rover Repair: 94 Disco 300tdi fuel blockage?, vehicle speed sensor, throttle position sensor

Question
hi ,
thanks very much for your help, and replying so quickly. i just read that it may also be the fuel pump relay do you think this could be the case? someone on a forum also suggested that there could be a wire shorting out somewhere, since reading this i have checked and my rear lights are out (only the position lights though) thanks again
matt
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
hi,
I'm having problems with my disco its a '94 300tdi commercial. on two separate occasions now the car has spluttered and stopped, both times when goin up a hill. it seems like a fuel problem as the first time we fixed it by bleeding the fuel line, i think it could be a blockage caused by maybe some dirt in the tank, just wanted some advice as to what it could be if it wasnt that! any help would be greatly appreciated thanks
matt

-----Answer-----
Hi Matt,

seems like you don't have enough fuel under load.  Could it be something other than a blockage?  Maybe the fuel pressure is not being maintained, caused by a weak or faulted lift or injection pump.

IF, as you suspect, your fuel lines may be blocked due to contaminants, you have to check the fuel lift pump and most likely, the fuel filter/sedimenter.  

Does your 300tdi have EDC?  Some early UK models do not.

IF yours has EDC, maybe a sensor is faulted.  It could be the injection timing, airflow, engine speed or vehicle speed sensor.  I've had trouble with my throttle position sensor (TPS) before.  Then there's the turbocharger boost pressure sensor.  There's even a remote chance that the timing belt needs service/adjusment.

If any of your sensors are faulted, you may need the services of a fuel injection specialist.

I hope this helps,

JohnMc


Answer
Hi Matthew,

I'm always surprised by the affect wiring shortcomings have on the electronics of our vehicle.  A burnt out bulbholder for the left rear brake light can take out all or most of the dashlights.  With this in mind, I'm sure a short that affects a component 'in series' with the fuel delivery system could give similiar results.

Finding that short is the trick.  You'll need to pull fuses and monitor line voltages to determine if this is true.

Best of luck,

JohnMc