turtlepeas

I have what seems to be a bad ignition coil, yet I don't get any "cylinder misfire" codes. I originally had a cylinder 1 misfire code and tried the usual methods to fix it: swapped coil packs and changed spark plugs just in case, to no avail. I then changed the spark plug wireset and the issue was solved. All is well at this point and the car is running smoothly.
A few weeks later I needed to remove the coil at the number 5 spark plug and the connector all but crumbled in my hand. There was enough of it left that I could very carefully put the prongs back in what was left of the housing and connect it back to the coil. This seemed fine until a rather harsh idle and drive manifested itself. With the engine running if I touch the top of any coil I can feel the steady tapping of the plug firing. Not so on the coil at spark plug 5 though. Of course its the bad connector I think, which I replaced with a new one, but the spark plug there still isn't firing. From my research this points to the coil indeed being bad. But from the half dozen videos I've seen a "cylinder misfire x" would show where each person's bad coil was; not so for me even though I don't think it could be anything else.

tldr; if a bad spark plug or faulty wires can manifest as a cylinder misfire code, shouldn't a bad coil pack throw a code as well?

Arsenii

Hello,

Sorry, but your explanation seems kind of out-of-place. As I understood, you have a 1MZ-FE engine with wasted spark system (3 coils for Bank 2 and 3 wires for Bank 1). If that's so, there are only cylinders 2, 4, 6 that have coils, cylinders 1, 3, 5 have ignition wires coming to them.
CEL will be triggered only if the misfire count will reach a certain point. What you can do is get yourself an OBD-II scanner that can show real-time misfire count, check it with current setup, and then swap coils around to see if the other cylinder will start to misfire. If so, it will indicate a bad coil; if not, check the wiring that comes to the coil.

Also, how exactly did you replace the broken connector? Did you replace just the housing or the whole connector? Please refer to this post to learn more.

Hope this helps and best of luck!

turtlepeas

Hi, Arsenii

Yes, you're right; I didn't give a good explanation, that was all over the place :/ A couple of months back I developed a really rough and choppy idle, and had a cylinder 1 misfire code to show for it. My first guess was to change the spark plug, which didn't solve the problem. Once i changed the wireset the issue was solved, no more rumbling idle and no more code.

My current problem "seems" to be similar: same rough choppy, shuddering idle and acceleration. I think, ok I've seen this before, but I don't get a code. My guess is that it's my number 6 cylinder. The reason I think it's that one is because that is the connector that crumbled on me, where it connects to the coil. It wasn't broken enough to where it wasn't making a proper connection to the coil, but I replaced it anyways just to be sure.
Another reason I think it is the number 6 cylinder is when I hold a finger on top of that coil I don't feel the steady firing that I feel on the other two coils 2 and 4. As of this post, I replaced the #6 coil with a salvage one just to test and although the car seems to not run as rough, it's still rough. And there is still no firing I can feel when I touch it.

The connectors I ordered came with wiring attached to them. According to reviews on the part, people were saying that they simply pulled out the existing wiring from the connector housing and just attached the connector onto the prongs in their car, which is what I did. Seems to be a perfect fit.

I'm not sure how to proceed though. I'm wondering if (big if) a poor connection from the crumbled connector somehow compromised that particular wire and if I need to replace said wire OR if I need to buy a new, not salvaged, coil. I'd hate to start throwing parts at this without a better understanding.

Arsenii

Did you change only one spark plug? That is not how you suppose to do it, if you are changing one spark plug, all of them have to be changed. What is the mileage on your plugs?

Again, the easiest way to approach it will be to get an OBD-II scanner that can check ECU's live data. If you will spot a misfiring cylinder, try swapping wires or coils around with the other one to see if the issue will transfer to the other cylinder, that will be a clear indicator of a bad coil or wire.
If, on the other hand, the issue will stay at the same cylinder even after the swap, it will signify an either bad spark plug, or a bad wiring to the coil.

I asked about a connector because you can actually replace the connector housing without having to replace wire terminals. The post that I attached earlier contains Part Numbers for all the connector housings in the car, as well as for all the wire terminals.

Hope this helps and best of luck!

turtlepeas

All of the plugs were changed, and are new Arsenii. I'm using the Torque pro app for a scanner, and I'm not sure about how much live data it provides. I'm guessing that all OBD2 scanners aren't equal and maybe I need to invest in one that's more robust or provides more info?

I haven't tried to troubleshoot after installing the new coil so I'll swap them around like you mentioned and see what I can see from there. And now that I've been thinking about the problem for a few days now, I'm wondering if a misfire of any kind is even the problem since don't have a code. The ONLY reason I believe this to be the case is because I can't feel the coil firing and the car feels like it's not running on all cylinders. Is that even the correct train of thought in your experience?

As for the connector I did indeed replace the housing without having to replace the wire terminals. Your post would have helped me do it easier though since I didn't do the needle prying technique.

Arsenii

Sorry, it sounded like you just replaced only one spark plug..

Below is the video that shows how you can check for misfire using Torque Pro app. You should also make sure that your OBD-II scanner is actually compatible with the app, here is a complete list.


Hope this helps and best of luck!