The Petting Zoo (Suppository Depository)

Funny that bank 1 is DS and Bank 2 is ps which is opposite of the norm. Guess Toyota wanted to be weird with this one.

 

I put this same pic in your build thread.

 

I’m gonna try to diagnose a P0305 code - misfiring #5 cylinder.

Hopefully it’s just a spark plug or an Ignition coil.

My question is: What would cause an ignition coil to fail?

 

I saw that. Mr..Googlepants works wonders!

 

Thanks!

Yeah I found a pic earlier this morning, but it didn’t indicate front of vehicle.

 

Age. They don't last forever they are constantly charging and discharging eventually wearing out.

 

I think they should last more than 14 years. What a rip off Toyota!

 

Additionally if something is grounding from bad insulation an overdraw of current will cook it as well.

Edit: Really any overdraw of current will.

 

Ok. I’ll bite.

What would cause an overdraw of current?

 

A short. If you have a bad plug or cable it can increase resistance which leads to heat which leads to insulation breakdown. Then it's free to short out.

 

OK. Need an opinion here.

I'm gonna try to fix my cylinder misfire with new plugs and a new #5 Ignition coil.

It easy and cheap to replace all 6 spark plugs.

But what about the ignition coils? Since the truck is 14 years old, should I just go ahead and replace all 6 coils and be done with it?

Are the other five current coils due to fail due to age?

The best deal I could find for OEM Denso coils is at Advance Autoparts. With a 25% coupon code, the price is $47 each.

 

What I’d do before anything is try swapping ignition coils and see if the code follows the “bad” coil.

 

Try clearing the CEL with an obd2 code reader. Swap out the coil to another plug then turn the truck on. If yoy have the misfire on cyl 5 still then you plug is bad. If it changes to the cyl you swapped the coil to then you know for a fact it is your coil.

 

What Randy and Jaime said.

 

What Randy and Jaime said but I'd move that plug to a different cycl. also if the code follows either the plug or the coil then you'll know which is causing the issue. If it stays with #5 then you either have something mechanical wrong with that cycl or a bad injector.

As far as replacement of all the coils when I turned wrenches and we had a vehicle with the age and mileage of yours then I'd recommend replacement of all 6 but it is not necessary. They all will eventually fade and die. You also got to think it's a possibility that the coils have weakend over time and the spark isn't as strong as it once was. It's hard to tell unless you put them on an oscilloscope and look at their pattern.

 

Hes going to need a basis to look at. Rise time, peak voltage, etc...

 

Yeah but you can compare the old ones and see any annomolies in the old ones. Yes having a baseline of what a good new one looks like is ideal

 

Good point. Any working baseline is good enough for troubleshooting. Hopefully Lloyd has access to an oscope.

 

No oscilloscope.

I’m going with simple first.

1. Switching the #5 coil to #3 to see if I get a misfire code on #3
2. If yes, then replacing the bad coil with a new coil.
3. If no, then change out #5 plug to see if it fixes it.
4. If new plug fixed problem. Celebrate. Then replace all plugs and hold onto my new coil as a spare.
5. If still getting misfire. Then I’ll come back to you guys.