Horrible misfire on cylinder 5, anyone help?

[4RunninRoman]

I've been trying to figure out why I have a misfire on cylinder five. I've already changed plugs and wires, cleaned maf, checked for vacuum leaks and unmetered air.

I just need some suggestions because I'm totally stumped. Any help?

 

[kaceman]

its either the injector or the coil

 

[Stick Figure]

Simplest way to check is two swap the coil to one cylinder and the injector to another and see which one it follows.

I would assume if it is the coil though that you should have a misfire on two cylinders and not just one since the system is a wasted spark set up.

Other possibilities are cam/crank sensor problem with either the sensor, the trigger, or the wiring involved.

A leak down would be a good idea as well if the problem doesn't follow either the coil or injector.

 

[Baja Runner]

Yep. You have a coil or injector problem. Easiest method is said above. Just swap the rear coil with another one, and see if the misfire code changes to another cylinder.

If you want to just test the coil, and other ignition parts, go here:

Start on page 4.
http://ncttora.com/fsm/2003/Repair_Manual/03tacoma/ig5vzfe/ignsy/ovi.pdf

Most likely the coil is your issue. It seems to be a very common problem with the 3.4L. I have replaced 1 injector that mechanically failed on a buddies 3.4, but testing/changing the coils are about 10x easier to do, so make sure you exhaust that before moving to the injectors!

 

[Smog-guy707]

If u have carb or brake clean u can spray it into the engine through a vacuum line. If the engine runs smoother while u spray it means the injector is bad and not firing. I thought if it was d coil it would miss on two cylinders? But as stated above u can swap with another cylinder and see if it fallows. Now if its a mechanical problem....a quick check is u can disconnect the ignited and crank the engine and listen for a cylinder that is out of sync....just my. 02