Had this problem for years. My 16v always starts when cold but seems like it has so much comprehension when hot that the starter motor struggles to turn over the engine.
Usually this will start it but some times its like the battery goes flat.
It has had a new upgraded battery, new starter with the brass spigot, i have put on heavy duty earth cables direct from battery to starter mounting bolt, i have cleaned up all connection and I have tried retarding the timing. Im not sure what to try next.
Has any one else had this problem?
I'm wondering whether I need to upgrade the starter motor.
I have had this car 15 years and would say it got worst when I put in new starter about 3 years ago.