I have a 1994 Ford Falcn Futura and it has trouble starting and when it does it idles roughly for a hort time and then all is fine. The starter motor and battery are reasonably new. Sometimes when I turn the ignition, the car tries and tries and tries to kick over and when it does, it idles roughly for a short time and if I I rev it it seems to settle then all is good. Other times it might start immediately but it will still idle roughly until I kick it with the accelerator or just let it go. It doesn't happen when I am stopped at say a set of traffic lights. I don't believe it's an injector problem as I don't have any problems cruising, it's only when it is trying to start or just when it starts. The mechanic changed the fuel filter and yeah there was some crap in there, but that didn't fix the problem. Any thoguhts?

Oh yeah, I should also say this started and has got worse since I had a new head gasket put on. Thanks

Was the head gasket done properly and the head machined? A small crack or warp can have water leaking into the cylinder head, giving a starting problem. When it burns off it'll run fine and usually only takes a few seconds?? Just a thought