About 1 year ago I had a problem with my 2000 TL (I had about 70,000 miles on it then) when the engine was jerking during the acceleration sometimes. Car electrician has checked with the scanner, which showed cylinders misfiring. I was advised to change the spark plugs. So I replaced them with the new original NGK plugs.

Now I have about 90,000 miles on TL and it started to do the same all over again, i.e. engine jerks on acceleration.
I've asked Acura dealership how long the spark plugs lasting before they needs to be replaced again; they said that the NGK originals are good for at least 60,000 miles.
So it seems that something else is causing the engine to jerk on acceleration.
Can someone out here hint me on cause?
Thanks