low rpm flat spot?

[300bucks]

I notice that from 2-3.5k rpms it seams to be somewhat flat in acceleration, after that, it pulls hard and strong... Any ideas what this could be? I changed the plugs and air filter, I know I should change the wires/ cap/ rotor... will this cure the problem? Or could it be something else....? Thanks for the info..... On a good note, I've stripped the interior, chisled out all the tar on the floors, and lost close to 200lbs. Def a noticable diff in acceleration/braking and road noise.... Still no rear window, waiting to get some $$.... PICS coming soon!

[corn322]

might be coolant temp sensor.