how can i fix my rover 25?

have a rover 25 w plate with 67k on the clock had cambelt and pullies done 6k ago had a compression test done pot 1 is about 100 pots 2,3,4 are up around the 160ies so no pot 1 is down but the main problem is when its cold it stalls the min i take my foot of the gas and it takes longer to get going it only does this once then drives ok bit down on power and runs a bit lumpy timings been checked and ok