1990 Range Rover 3.9 v8 Starting and runing problems

[Tubs]

Hi, I have a 1990 v8 vogue which I have starting and running problems with. I know this is because I flooded the engine with water while off roading earlier this year. But after taking the plugs out and clearing the water it started and ran ok for a few weeks. After this it would start run for 3-5mins and cut out. I have changed the plugs and was getting what looked like a good spark. Still I had the cutting out problem, so I started looking a the fuel system and I changed the fuel filter. Still having the same problem I left it for a few more weeks. Now I go to turn it over and it fires but it will not run. Can any one help please?
 
Thanks

[Range Rover Blues]

I did that, turned out it was the coil, once it got hot it started playing up.  Give it a try.

[Tubs]

Thanks, I forgot to say I changed the coil as well for a brand new one. It still does the same when you turn the key it will fire but it won't run. Could it be some sort of sensor stopping it from running?

[gingernutsv8]

water in the fuel tank??? drain the tank and put fresh fuel in   

[Tubs]

I thought that water in the tank could be the problem but when I changed the fuel filter I took a bowl full of petrol out of the tank and there was no sign of water on top of the petrol. But Im no expert on how the water would sit in the tank so this could be the problem. I will give it ago.

Thanks

[gingernutsv8]

water sits at the bottom of the tank so if it sits where the fuel pump is it won't suck it up. if you undo the drain plug in the tank catch the fuel in a big bowl so you can see if there is any water in it