Car jerking when stepping on accelerator...help please

Hello guys,

Nissan Sentra 2002. When I continue to step on the accelerator when the car reaches about 60kph, it would start to jerk. It's more or less fine when I don't step on it so much, which means I'm limited to 60kph or below when I'm on the highway.

I'm not seeing any warning signs on the dash board, nor do I hear any weird noises.

Your advice is greatly appreciated.

Thank you.

:confused:

Check your ignition system first. Then go from there.