Well I picked up a used 4runner with 130k miles on it. Its an extremely clean vehicle. Here is my issue and I believe I know the answer but I wanted to run it by everyone. It had a code for missfire on cylinder 5 when i got it. Well I went home and found single ground plugs so I got dual electrode plugs and moved cyl 5 coil to cyl 3. Now I am getting a missfire on cyl 3 which tells me its a problem with that coil pack right? Now while I am driving everything feels great other than around 55-58mph and 1700-1900 rpms. If you try to hold that speed it starts feeling like the tranny is hunting gears but I think its the missfire happening. Can anyone confirm this? I dont feel this sensation at any other speed or rpm. Thanks in advance.

Jason

 

Just to let everyone know this ended up being my #5 coil pack which I moved to #3 position.

 

Glad you got it figured out. Normally that misfire at cruising speed in overdrive happens with old plugs and wires. Since you have changed the plugs I would have thought that problem would be gone. How old are the wires?

 

I have no idea, I purchased the 4runner 2 weeks ago. They look in great condition like they are not very old but looks could be decieving...

 

Check the wires for a date on them. If they are originals they will have the date. If you don't see anything I would just replace them so you know they are new and good.