I have a 97 4runner with about 200+ on it.
The question I have is that I have had to replace the Number 2 Coil pack about once every three months. I have done this about 2 times now and it is getting time to do it again. I would like to fix it for good this time since I have the time to do it and another car to drive while I get it fixed or poke around at it more.
After about 2 months with the new coil pack this will happen. When I start the truck in the morning it runs really rough. Like it is running on only 5 cylinders instead of 6. After about 30 seconds to 2 minutes it runs smooth.
Right near the 3-month mark. It will not run smooth until about the five minute mark and you can here it miss every once and awhile at an idle thereafter.
The out come is always the same the Check engine light comes on and my reader always says it is misfire on one of the cylinders. What happens is that the cylinder that the Coil pack sits on misfires but the opposite cylinder will fire with the same coil pack.
I have tested the coil pack by putting it on a different cylinder and reset the ECU. Same thing happens Check Engine light comes on after a short time but the misfired cylinder moves to where ever I moved the coil pack. So I know the coil pack is bad but just cannot figure out why it is always the same one and how to prevent it from burning out after another three months.