Vauxhall Cavalier 2SRI?

Why does my cavalier 2SR1 refuse to restart after a very short run and a 30 minute stop;
Refuses to start after a 5 minute run, turns over ok but seems as if choke problem although no choke fitted on this model, might pop and as if running on 2 cylindres if it does start, once running all is ok
Will run perfectly on any other journey-just faulty after a short run and a short stop (as in shopping for 30 minutes)