Random Cutting out!!!

Hi I hope someone can offer some advise. I have a 1996 P38 4.O SE which I have recently fitted a brand new engine into (Pig of a job but thats another story!).
The engine runs really well, however it has a random intermitent problem of cutting out. It does it when hot or cold and can be re-starterd straight away.
Yesterday I went on a 200 mile round trip with no problems, however when I got home ten minuits later I went down the road and it stopped again. The engine just dies no spluttering and the dash lights come on.

I have replaced the idle stepper motor and had the adaptive values reset at my local 4x4 garage. The electronic diagnostic test found no faults! I can see no other obvious problems!

Can anyone help? Is it electrical or fuel? Need help my wife now wants to me sell it (no way, I need it fixed) Thanks Neil

I had a similar problem about a year ago and it turned out to be the fuel filter, worth changing it if you are not sure when it was last replaced.

Another well known problem is the fuel pump drawing in air, hard to diagnose unless you swap one out.

Thankyou for the advise. It is one item I have not changed. Will keep all informed when I change it to see if the problem goes away!