In cold mornings, my car starts OK but the engine sign stays on and it chokes along with smoke trailing behind for about 5 to 10 minutes, depending on how cold it is. After that, when I turn off and start again, the engine sign will usually go off and the car will be fine for the rest of the day. If the sign is still on, I'll have to choke along a bit longer. Have done a diagnostic test in a local garage but nothing unable to locate anywhere faulty. A mechanic suspects the fuel pump but not sure. Please advise.