My housemates got a ford fiesta, everytime you try and start it first time it refuses to fire and pops slightly. As soon as you turn the engine over again it fires immediately. This irritates me alot in the morning specially because its loud and she goes to work mostly at 6am i was wondering if anyone owned a 1.25 fiesta before or knows what it could be.

I was initially thinking timing, maybe coil packs leads or spark plugs but she said she had it serviced about 7 months ago and its been going on that long its just bugging me as i said id have a look at it. Any other ideas?