Freelander TD4 55 plate

I have an intermittent fault that I need help with. On an odd occasion the engine turns over but doesn't start. I know when its not going to as when I turn the key, if the Engine Malfunction light doesn't go out, it doesn't start but turns over.
A few days ago I was driving 40mph when the revs dropped, the EM light came on for 2 seconds and then went out, the revs picked up and all was ok for the rest of the day.
Whether I imagined it or not but a few times over a week or so when I lifted my foot off the accelerator, the car stopped pulling more than I thought it was going to, but this was just for a split second as I put my foot down again......... I'm getting old so that may be only in my head!
Non starting can be any time of the day but recently when it wasn't starting, I checked the fuel pump relay was switching 12v onto the output contact which must go to the pump.
I wondered if it was a sensor that is checked on initialization before starting.

maybe first stages of fuel pump failure...

as for non starting, could be an injector leaking back. if you carry out a leak off test, that will say for sure.

Are you saying that by turning the key to normal running position, not trying to start the engine,( this is when the EM light doesn't go out but should ) that fuel is pumped through the injectors before the engine turns?

no, the low pressure or lp fuel pump runs when the key is turned to the on position, which provides diesel under pressure to the chain driven high pressure or hp fuel pump, which is driven from the crank on the engine.

Once you turn the engine over with the key, the HP pump then sends fuel at high pressure to the injectors.

Crucially, then engine management system monitors the pressure at each injector. If it detects a serious imbalance in the pressures, such as caused by a faulty injector leaking back, it will not allow the engine to start.

However, if a can of easy start or similar is sprayed into the air intake, it will ignite in the cylinders and cause the engine to run. once it is running, the engine management system no longer checks for this imbalance. BE WARNED, using easy start to start the engine is a BAD THING and should only be done once or twice. (don't know, was just told this when it happened to mine)

good luck

Thanks for that, but as the EM light doesn't go out when I turn the key to first position before cranking the engine, the fault is being detected before the engine is cranked.
I did buy a manual from Halfords and I see there is a long list of sensors that the engine uses, so I'm inclined to check those if I can find them and they are easy to check when the thing doesn't start next.