Help rover won't say running

[GLENNO76]

HI I HAVE A 1990 RANGE ROVER COUNTY
I was driving home from work and it just died. it did this once before then restarted and ran fine for 3 months. now it will start from cold run for 5-10 min. then just shut off and won't restart for hours and then only run for 1-2 min then die again.Then nothing until next day when it will do same thing all over again. I have replaced fuel pump, checked all earth wires I could find. I see no codes at all. I have checked the fuel pump relays & Clean air filter unit they are ok. Can anyone HELP please I Need my car for work asap!

Thank you ! HELP HELP HELP!!!!!!!!!!!!!