Cranking too much

Apart from the obvious comment that it makes you blind, I'd appreciate some input as I struggle to find the answer to my current dilemma.

Vehicle: '03 RR Vogue TD6 3 litre diesel auto.

For a while I'd been thinking that it was taking a long time to fire when starting. It didn't seem to matter if it was hot or cold, nor if the time between each start was hours or seconds. It still seemed to take the same 3-4 seconds of churning of the starter motor to get her going. Then one day, the other half was out and about, making several shopping calls when it decided not to start, and no amount of churning would persuade it otherwise. I went out and failed, as did the AA man who was called out.
We were finally relayed back to a local garage who suspected a crankshaft sensor and this was duly replaced and the engine now starts again, but still with this delay while the engine spins over before starting.

Are there any other L322 owners with the same problem? Is it normal to have this delay in starting? Can anyone shed any light on a solution?

I would say its one of 2 things, your battery (put a new one on the higher the recommended amp the better) or your starter motor, they seem to lose power when they are on their way out, but it could last you another 10 years, but its not turning as it should ( slowing down) and doesn't give enough power to really spin the engine over 100%

he dunt actually say its slow in turning over

True he don't, but on 2 other cars it has happened to me, and tbh, i didn't notice it slowing down either, maybe its because its a gradual process i don't know, or its a torque thing, but that's all i could think of at the time

or it could be glow plugs.

Just quick post to say that my problem has been cured, after a couple of false starts. First it was suggested that the crankshaft sensor could be faulty - that was changed, but no real improvement. Then it was suggested on a couple of RR forums that the culprit could be thr secondary fuel pump not delivering enough flow to reach the pressure needed by the common rail system. On the right track, but even though the pump had noisy bearings, it was pumping ok - I changed it anyway for a new quieter one - then an injector leak test showed that number 6 injector was leaking like a tap, not allowing the pressure to build up properly in the common rail fuel system, and until the pressure is high enough, the engine management won't let it fire.
Solution - one new injector, and it now fires first time, every time, just like it should.
Hope this might help anyone with the same symptoms.