RPM Fluctuation


#1

My 2000 Chevy S-10 4x4 has been driving rough for a few weeks. The tac revs up and down while I’m driving - feels like it’s losing power, then catches and continues on normally. I just put new tires on it (31 10.50 - the same size as the ones that came on it) but I’m not sure the problem is related. Any ideas?


#2

I have no idea how new tires same size could cause rough running.

Do I understand that when you are under power, as opposed to coasting to a stoplight or otherwise reducing power, it runs rough at times?

I ask to eliminate the possibility of an idle control problem, but for sure that would not be the case when you have the throttle down a ways, only when you let up on the throttle in normal driving where speed varies in traffic. Just want to make sure we are speaking the same terms.


#3

Automatic or manual? Sounds to be a transmission issue.