Not being as techie and experienced as others on here I would check the simple things like battery life, ur terminal connections etc.
Aside from the main relay replacement there is also a recommendation to replace the fuel pump rectifier as well (wee square metal box on rhs of engine hatch). Could be this maybe fuel pump issues or indeed a faulty relay unit. Due to the age of our cars things like this will need replacing etc
Just hope u get sorted ... Keep us posted on diagnosis
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