Hi, i just bought a second hand ford lynx M.T 2001 model, the problem is rough idling specially when air con is on, and its jerking when at slow speed.

SOURCE: 2001 ford 4.6 liter idles rough sometimes dies

may need 1 0r more coil packs replaced,or it could be what happened to my 2000 4.6---1 lifter expanded out and wouldnt collapse,causing the rocker arm to fall out of place and the valve could never open...try unplugging 1 coil pack at a time while running and listen for a change in the way it runs,if there isnt a change then its probably a bad coil pack,find a cylinder that runs and swap the coil packs,if no difference then its probably the valve staying shut.

SOURCE: Rough idle, and jumpy ride

check the pcv hose that connects in the rear of the intake

SOURCE: my 2001 c200 kompressor shakes

see plug wires HOW at night start the engine open the engine hood it should be dark so that you can see any spark on the cables

SOURCE: 2001 Cad DHS 4mo. ago

Hello and welcome to FixYa!
Is the check engine light on? If it is then the problem can be on one of the sensors and I suggest that you have it scanned by an OBD reader to know the exact fault for replacement.
Although I suspect that the coil pack is faulty that's why this issue occured. Irregular current supply to the plugs can be expected when the coil pack is faulty. One good reason why it stalls.
Hope this helps and thank you for using FixYa! Have a good one!

SOURCE: Idle speed rough black smoke

More information needed, what model vehicle and what engine? Fuel injected or caburettor? That sort of info.

Terry