Please someone tell me what this fuse wire is in my wiring harness. PICS
 

I have been searching a cylinder 1 misfire for over a year now. Posted a while back about this, link below, but last final thing is tracing a short in my wiring harness. I Started looking and I have this what looks like burnt fuse attached to all wires wrapped in tape in my wiring harness, Someone please let me know what this is and if this could be causing my misfire.

Just been lost, please let me know what this could be.
Thanks

My misfire thread,
https://www.clublexus.com/forums/gs-...-please-2.html

https://cimg7.ibsrv.net/gimg/www.clu...8d2e32f8fa.jpg
https://cimg4.ibsrv.net/gimg/www.clu...00c5e404dd.jpg
https://cimg8.ibsrv.net/gimg/www.clu...156c2f13ad.jpg
https://cimg1.ibsrv.net/gimg/www.clu...3d986388b1.jpg

It does seem to be in series with your coil wiring. Maybe try removing it and putting the wiring back to normal? I don't know what it is, but it doesn't look right.

I just opened wiring harness back up, it doesn't look like any of the wires are going to coils, 3 are going to left of engine, rest about 6 are going right in the harness, this is facing engine.

I just need to know what this is, that's all, someone was smart enough to put it in there, even my toyota/lexus tech told me to take to dealer and has no idea.

That's generous.

Great, just need some help with what it is and if its effecting my misfire, thats why Im asking, thanks

Bump, anybody think this is related to my misfire ? Or anyone can tell me what it is ?

I'm no help but I have them in my GS as well

That helps me a little. I just cant figure out this misfire, and last thing would be some short in wiring, But I have never seen that before, but if you have it then guess I feel little better. I just thought it might have something to do with my misfire.

I'm by no means a lot the pro here but I doubt it has anything to do with the misfire. If I remember correctly I have come across that in several locations throughout the vehicle.

Have you tried another ECU in your trouble shooting efforts?

What have you done so far in an attempt to fix the misfire? You are very lucky that it's in the easiest cylinder to work with. Whats the mileage it's at. Have you done compression tests and compared to the other cylinders you can access? Have you swapped plugs with another cyl, then the coil that fires it, then the injector? If it is just that one cylinder, it's not the common broken coil connector not making a good connection. Try shoving the igniter connector in a little. This was the cause of an intermittent cyl 6 mis for a couple weeks for me. Zip tied it on good and hasn't happened since. Let us know what you have or haven't done yet. If you haven't done the swaps I mentioned, you need to until the mis follows the bad component. Otherwise it may be compression related if the mis never leaves #1.

Hey I had mentioned in my previous thread, sorry not on this one, But I have replaced plugs, wires, all coils, injectors, all factory lexus parts, compression on all cylinders are good, vvti solenoid. I have even swaped new coils and injectors with dif cylinders just incase I bought a bad New part, and still the prob happens. I have NOT replaced igniter, or ecu as a few have mentioned. I was just tracing my wiring harness, like another member mentioned and saw this fuse junction thing in my harness and looked very off, thats why I mentioned it.

I will now check igniter wires, and look at seeing if that could be the cause. I have taken it to 2 good lexus toyota shops, and they seem stumped and just say take to dealer, before I spend 600 for 3 hours of dealer labor, as they quoted me was a start to see the prob, IM trying my hardest now to figure it out.. Any other thoughts will be much appreciated.

That is the old style of a factory splice point. It is most likely for the engine grounds to converge onto. It is a normal part of the harness. My advice to you for the misfire issue would be to replace those blue spark plug wires first with factory denso wires. I would be reluctant to say it was a coil because that engine is a waste spark system so a coil would most likely affect 2 cylinders. I would also say an igniter is unlikely because it controls all 3 coils so it should set a random misfire code accompanied by a misfire for each cylinder individually. If replacing the spark plug wires does not fix it, I would check for wiring issues with the cylinder 1 fuel injector such as poor pin fit at the connector or a poor ground. I'm ruling out mechanical issues for the moment because something like that would be a constant issue. If you had a flat cam lobe or a burnt valve, or poor compression in any other way, that would happen all the time no matter what. Hope this helps!