To start off I know my ignition coil is bad b/c my tach. gauge goes crazy some times. I just felt this tonight. It felt like the engine was getting kicked up maybe hundred RPM's every 10 seconds or so when at a constant speed. Now as I feel that the tach gauge is bouncing around(it has been doing this for about a month but I have never felt the kicked up rpm's). Then when the gauge settled down and returned to normal I did not feel the extra hundred RPM kick. Is there a tranny problem there. Oh ya its an auto v6

Sorry if that sounded confusing.

 

a bad coil would not give the engine an increase in rpm try resetting your computer but it is possible it is a transmission problem, what is the color and level of the fluid and how long has it been since it has been changed?

 

Check ignition switch, syptoms are gauges go crazy, the ignition (is not igniting properly) its an easy fix, if you hold the key up (i.e. turn it to between the on/start position) it should fix the problem, if not try something else. i had the same problem, lemme know if thats the case. eventually my car would not start properly, engine would crank over then die. until i figured out to hold the key up, driving stick is not fun when you have to hold the key up, and the wheel at the same time, believe me. Goodluck

 

You might need a new igniter in your distributor.