2003 v6 misfire

Hey Everyone,
I have a 2003 v6 RCLB that I bought a few months ago. I got a great deal on it but since I have owned it I have always had a slight misfire that u can feel at idle. The car has only thrown a misfire code once. I have already in the last few thousand miles changed the timing belt, water pump, air filter, cleaned the MAF, spark plugs, wires, coils and the injector for cylinder 3 which is the cylinder that the misfire code indicated. Anyone have any suggestions what to check next?

 

I see you say you changed the coil for that cylinder specifically. The tube bodies often crack, allowing spark jump, thus misfire. Was the replacement new, and did you inspect it for cracks in the body?

 

Yes, I installed all 3 with new denso coils. The only thing that I didn’t replace all of was the injectors since they are so expensive I only replaced the injectors on cylinder 3 which is what the check engine light indicated was the cylinder that was misfiring

 

Did you use spark plugs that look like this, or regular plugs?


V6 engine calls for the double prong like shown above.

Here's a link to the ones I used on my V6.

$10 NGK (4302) BKR5EKPB-11 Laser Platinum Spark Plug, Pack of 1

Link.

 

Yes, I used the dual electrode plugs

 

To rule out a strange coincidence...

Try swapping cylinder one and cylinder three coils just to rule out that you didn't get a bad new coil...

long shot and would be a helluva coincidence that it'd be on the same one that was missing.

 

Also, pull plug three and see if it's oily.
May have leaking seals?

I can't fathom a grounding issue only affecting one plug. I've seen stranger things happen.

 

Thank you for the suggestion. I actually already tried this and it still felt the same. No check engine light but just a slight miss at idle

 

Thanks for the suggestion. I already did this I noticed more soot on the plug from 3 compared to the cylinder next to it but no oil.

 

We are on the same page now which is good.

These are the new plugs? I'm not an engine expert, more of parts changer/mangler really...

It looks pretty fouled. You may be able to brush off the residue, and get good spark from the plug but it will continue to be fouled until the conditions creating it are mended. This is beyond my scope now. Perhaps @empty_lord would be able to help more than I would.

 

Yea, these plugs are only a few thousand miles old. Thank you for your insight and for tagging someone who might be able to help further

 

Fouling = incomplete combustion. Points to coil pack or injector problem, or less likely, head gasket problem.

 

a leakdown test would be the most logical step to make sure nothings wrong with cylinder 3 before proceeding

 

Report? Update?