Cold start problem 1997 2.5
 

Hi all, my 1997 2.5 has been providing great service over the last couple of months but has recently developed this problem.
The car starts and idles fine when warm but from cold it fires immediately the revs start to rise for a second then it cuts out. Trying again produces the same results, the only way is to catch it with the throttle and hold the revs at 1500 rpm or so. After driving a very short distance it will idle fine and then drive perfectly. Before this it always started perfectly from cold and quickly established a steady high idle.

Any help much appreciated, Steve.