TD5 cut out won’t start

My TD5 cut out while driving. No post warnings, just a clean cut. Cranks fine, but fuel pump only runs if I shortcut the relay. Even when the pump is shortcut the engine does not fire. Any ideas?

The fuel pump power supply is obviously suspect, but you might want to check the battery voltage and get a diagnostic check in order to rule out the crank position signal or the ECU itself. You might also want to check the red ECU plug for oil.

Thank you! Plugs already cleaned, and battery re-charged over night. No difference. Will plug in the Nanocom, but do also suspect the ecu died

Check the cleanliness and tightness of the relays. Also check the earth near the ecu is clean and tight.

More, non starting TD5 info here:
https://www.landyzone.co.uk/land-rover/advice-needed-2001-td5-wont-start.361736/

wireman said:

Check the cleanliness and tightness of the relays. Also check the earth near the ecu is clean and tight.

Click to expand...

Do you get the yellow light on the dash when you first turn on the ignition?
If not then probably the main relay
I agree with the previous message, it's worth pulling out the relays under the drivers seat and pushing them back firmly.

Which Main relay ?

On the Defender there are yellow relays under the drivers seat, one is the main relay, you might check the bonnet switch also which is made when you close the bonnet.

Does anyone have the part number for the yellow relay under the drivers seat please

wireman said:

More, non starting TD5 info here:
https://www.landyzone.co.uk/land-rover/advice-needed-2001-td5-wont-start.361736/

Click to expand...

Problem not solved yet. Doubt it is lack of voltage as the car cut out while driving and a test with a fully charged battery made no difference

raywin said:

On the Defender there are yellow relays under the drivers seat, one is the main relay, you might check the bonnet switch also which is made when you close the bonnet.

Click to expand...

sorry for my late reply. All done no difference.

Is the fuel pump still not working properly? Have you purged the system of air fully? Replaced the air bleed valve?

The fuel pump has worked all along, but it does not fire

Sorry I thought the pump only worked if you shortcut the relay.
What readings did you get from the Nanocom?
If nothing and your battery is giving a good voltage (12+ volts at start) then that rules out crank position sensor feed and ECU, and pretty much leaves a fuel issue.
If the pump runs then check it is giving 4 bar at the gallery (plug into the fuel temp port).
Run through the full purge system (ignition ON, but don't try to start, pump the throttle until the MIL flashes and then leave for 5 mins to purge - if you hear air then that is a big clue).
Replace the air bleed valve in the fuel filter housing.
Replace the injector washers.
If you suspect there is air in the fuel after that lot then search the fuel lines for a small leak where air can get in.

Sorry for my late update! The ECU was toast, a burned resistor !