Still chasing missfire....UPDATE....SOLVED

[rusty ol ranger]

I put in the new distributor...after swapping TFIs...new dist had a black module...

Put it in, timed it, still ran like shit.

So on a whim i started cutting tape and pulling off plastic tubing off the wire harness...what i found was...interesting...

After discovering this (i also checked power at the coil, coil pulse, and a few other things) i decided to pack it in. I fired it up and noticed it was idleing really...really...smooth. Like...smoother then ive felt a 2.9 idle in a long time.

I took it for a 4 mile drive. Didnt miss once. Tons of power. It is spark knocking though...im not sure if whatever was shorting out in this mess was able to throw off base timing or not...im gonna check that monday.

So in conclusion...i think im going to split some heat shrink and put over the bare shit, then poke it all back in some fresh convaluted tubing...and roll with it.

 

[alwaysFlOoReD]

I've used liquid tape in a case like that. Two layers with drying time in between. Then cover with self fusing tape.

 

[bobbywalter]

yeah. use loom tape.

those are the factory hammer splices and do fail at this vintage, its why source term continuity checks are needed. worse is high corrosion.

https://www.summitracing.com/parts/...mm2v4xtTstYCho8nzeawy_ICF7W8yYh8aAsiYEALw_wcB


i would not consider it solved just yet though.

 

[rusty ol ranger]

yeah. use loom tape.

those are the factory hammer splices and do fail at this vintage, its why source term continuity checks are needed. worse is high corrosion.

https://www.summitracing.com/parts/...mm2v4xtTstYCho8nzeawy_ICF7W8yYh8aAsiYEALw_wcB


i would not consider it solved just yet though.

I would of never guessed those were factory.

Ive got some of that kind of tape at the house already...but thats not what it was wrapped in...it was wrapped in standard electrical tape....which is what led me to believe those wernt factory.

The only other thing i can think of that mighta stopped the issue was when i jammed my dvom probe in the backside of the coil plug...like maybe one of the wire plugs wasnt making great contact...but i figured that was a long shot.

Whats the hanging green wire in pic 4then?

 

[85_Ranger4x4]

Yup, factory splices. Mine used to have them too.

 

[rusty ol ranger]

Yup, factory splices. Mine used to have them too.

Well damn.

Guess its a good thing i asked before i cut and tried to fix them lol

 

[franklin2]

Well damn.

Guess its a good thing i asked before i cut and tried to fix them lol

They can get corroded over time and give a bad connection. If they need to be redone, do it. Slide some shrink wrap up on the wires after you cut them, solder them together and then slide the shrink wrap over them and shrink it.

You will probably find the solder does not want to stick to the copper. That shows you how old and corroded it is. You can cut the splice, and then take the wires and lay them on a hard surface and take a knife and scrape the copper strands. Once you see some copper shine, the solder will stick.

 

[rusty ol ranger]

yeah. use loom tape.

those are the factory hammer splices and do fail at this vintage, its why source term continuity checks are needed. worse is high corrosion.

https://www.summitracing.com/parts/...mm2v4xtTstYCho8nzeawy_ICF7W8yYh8aAsiYEALw_wcB


i would not consider it solved just yet though.

Actually after rereading this when im not half asleep i should of added that the green wires had no sheilding whatsoever...the red ones had that friction tape stuff on them.

The whole harness was wrapped very tightly in hardware store style electrical tape.

 

[85_Ranger4x4]

The whole harness was wrapped very tightly in hardware store style electrical tape.

Kinda sounds like you have worked on this before...

 

[rusty ol ranger]

Kinda sounds like you have worked on this before...

My electrical skills have improved thank you very much.

Ive managed not only to rewire the 12v conversion on my 2n (it did almost catch fire a few weeks ago...unrelated) as well as splice on some new sensor plugs and even only took 45min to get my taillights working properly.

So....ha.

 

[Uncle Gump]

There is another factory ground splice that runs in a harness alongside the battery. It has both ECM grounds... engine ground and battery ground pigtail spliced together. I found it was bad on my Bronco II doing a simple wiggle test.

 

[lil_Blue_Ford]

Split the splices, put some glue lined heat shrink on, clean the ends of the wire with a scotch brite pad so you get shiny copper, flux it (do NOT use plumbing flux, it’s acidic and corrodes wires, use electrical flux and rosin core electrical solder), solder it, heat shrink and done.

 

[alwaysFlOoReD]

I would not use solder. Especially on old wires. Use a noninsulated crimp of the correct size and the correct crimper. Clean the wires mechanically, and chemically if you can. Make sure that a piece of glue lined heatshrink is in place before crimping. If you want I will take some pics of my tools I use for auto electrical and post.
Solder has a habit of wicking up under the insulation and creating a weak spot. No OEM says use solder. All spec crimps.

 

[rusty ol ranger]

Does anyone know if that green wire in picture #4 is supposed to be connected to the other green wires?

It looks like it either had the end broken off or was never connected in the first place. I cant find any other wire coming from the other side for it either

 

[franklin2]

You will have to trace it out and see where it goes. Lots of green wires under there. You said you had the harness tape off.