Cuts out very strange

Hi all,

I know you will be able to help so here goes, took my Mk1 tintop 1983 GTI 1.8 for a spin while driving did seem to stutter a few times but nothing obvious.
As I got home it suddenly stalled on the drive and would not restart I kept trying no joy.
I noticed the oil light flashing so checked oil all okay, disconnected the oil temp gauge still no joy starting.
I did get the car to start but it lost revs and cut out again.
I thought it may be the fuel relay possibly no fuel getting to filter. Ordered a new relay put it in and started straight a way took for a spin got 200metres up the road totally cut out I thought I heard a bang but not sure. Won't start same problem ticked over wouldn't start suddenly after 5 mins started and got home. I then left the car running on the drive for an hour no problems.
So for me that rules out the fuel filter being blocked.

Please any ideas before I replace every part of the car!

thanks as always