A non starting V8 disco.Ideas please!!!

Hi there
I'm new to this forum. I've owned 3 range rovers and now have an R reg Disco I 3.9 V8( for the seven seats).
Basically it won't start. There's petrol in the fuel line and sparks at the plugs but won't fire when cranked. It spins but doesn't start. I tried the tip of connecting a cable from the battery to the +ve side of the coil to isolate the immobiliser, but same result. The spark from the coil (held to earth) looks a bit yellow, could the fault be a weak coil ?
It was running fine, I parked it on Wednesday night, then Thursday morning nothing, nada, sweet FA, not a flicker.
Any suggestions would be most welcome.
Cheers
Terry

check the wires going to the dizzy and also the air gap inside the dizzy cap under the rotor arm. also check the air flow meter

Thanks for the reply. I'm not sure what you mean by checking the air flow meter. What checks can I do? I have a multi meter if that's any use.
Thanks for your help
Terry

when i 1st got My 96 V8i it didnt start either, it would turn over fine but just wouldnt start. When i put jump leads on it or bumped it, it started straight away, I changed the battery and the problem stopped. My old man seemed to think that it was because it was such a large engine it needed that little bit more "ooomph" to get it going, I had always driven vehicles with smaller engines which would have started if the starter was turning over that much. Just a suggestion.

If the spark is weak or absent, and the Dizzy end of things is ok, then I would be looking very hard at the famous imobiliser spider. Egzacerly the same thing happened with my Disco - weak yellow spark at the coil, next to nothing at the plugs........£5 for a spider bypass unit, and 2 hours under the dash sorted it fine.

put some petrol down the spark plug bore see if it will start up with some petrol in there. could be ht leads.

:search: There has been a spate of similar queries in the last week or so, the answer is out there!

It will be something daft, you might be in for a bit of time getting intimate with a multi meter and your wiring loom.

Thanks for all the ideas chaps.
I tried a booster on the battery, no difference.
The spark from the coil is indeed weak, so I'm going to try a new coil before the immobiliser spider route.
Any know where I can get a new one? I live in Eastbourne, East Sussex.

Cheers
Terry

Thanks to everyone for the ideas. I tested the resisitances through the primary and secondary windings and they were correct as was the voltage on either side. Nevertheless I tried a new coil and bingo! started on the button!
Again thanks for the ideas,
Cheers
Terry