melted engine wire harness (4 Viewers)

[Thomo]

I had a similar issue a while back. A few of my injector wires were meltes together and the copper strands were exposed. Turned out that when the copper strands vibrated against the EGR pipe they would short circuit to ground which would make the affected injectors open which in turn flooded the cylinder with fuel and hence the misfiring at low revs. This was confirmed when I pulled the spark plug on cylinder no.3 and it was covered in soot.

This is what my harness looked like:

I ended up cutting out the damages setions and soldering in new peices of wire, put heatshrink around it and then wrapped the harness in heat resistant tape. No more issues to date so I say just cut out any damaged sections. It was a pretty straight forward fix once I figure out what the issue was.

 

[Kernal]

Thomo: how did you reach the harness to repair it?

 

[yardbird88]

I can't tell where are those toasted wires in your picture. I hope mine is not like that.

 

[Thomo]

Thomo: how did you reach the harness to repair it?

Just removed the throttle body and egr valve. You have to disconnect the accelerator cable and kick down cable to get your TB off. These have barrel nut adjusters on them so I wrapped a bit of insulation tape around the barrel directly behind the locking nut before I removed it so I knew where it needed to be adjusted to when I put it back on. Pretty sure I saw that trick here on mud.

 

[Thomo]

Double post.

 

[Thomo]

Double post.

 

[Aids10]

Thanks for the heads-up; just checked mine and noticed the OEM heat wrap has just begun to disintegrate against the metal pipe exposing wires!
Looks like it was found just in time.

Would the best fix be to first wrap wires with Self-fusing Silicone Tape & then wrap all with Thermo-Tec Thermo Shield Tape?
How long should it take a shop to remove/replace EGR and complete fix?

Is there a way to replace the metal FHH that Tees off with flex hose to eliminate the problem altogether?

THX M8

 

[Hte2w8]

Thanks for the heads-up; just checked mine and noticed the OEM heat wrap has just begun to disintegrate against the metal pipe exposing wires!
Looks like it was found just in time.

Would the best fix be to first wrap wires with Self-fusing Silicone Tape & then wrap all with Thermo-Tec Thermo Shield Tape?
How long should it take a shop to remove/replace EGR and complete fix?

Is there a way to replace the metal FHH that Tees off with flex hose to eliminate the problem altogether?

THX M8

IDK if it's the best way, but thats how I did it exactly and it seems ok.

 

[bad man]

Does anyone know how to take the dash out. My engine wire harness has melted together above my glove box. I have taken everything out expect the dash can't figure out how it come out

 

[Tools R Us]

Does anyone know how to take the dash out. My engine wire harness has melted together above my glove box. I have taken everything out expect the dash can't figure out how it come out

What kinda car? This is dash harness work on a 4Runner.

 

[COYS]

Does anyone have a diy or step by step instructions with pics to ensure the harness doesn’t melt against the Egr? Many thanks.

 

[MoJ]

Does anyone have a diy or step by step instructions with pics to ensure the harness doesn’t melt against the Egr? Many thanks.

There’s not much to it. Buy heat wrap, wrap harness as shown in pics, zip tie said harness so it’s not touching the egr pipe. Is there something in particular you’re unclear on?

 

[COYS]

I understand there’s a method to tie it to the original plastic bracket? I want someone who likes things neat and tidy to show me their work. Pics would be nice.

 

[FJ80SRT]

I understand there’s a method to tie it to the original plastic bracket? I want someone who likes things neat and tidy to show me their work. Pics would be nice.

I second this, did you ever solve your problem?

 

[Tools R Us]

Tie the harness to the mount where the clip was attached.

 

[timchen]

Here's a link to the stuff that I used: Cool Tape

Costs about $15-$20 at the local O'Reilly's or Autozone. The worst part is going to be getting the EGR off but not as hard as getting it back on! I would inspect the wires and do any necessary repairs as indicated. Wrap the bundle with two full wraps or more. Mine threw a 306 but all my wires were in tact and no problems since first wrap and second wrap while doing my HG. Technically - if you remove the TB to do this - you'll need that gasket too per FSM. $5-$8 (your mileage may vary).

Good luck

Hi there, So you are saying that the you have a misfire but all the wire in the harness that near the edge was still look good? All you did was just re wrap the harness and keep it from heat then the problem goes away?

 

[adamgunn]

Hi there, So you are saying that the you have a misfire but all the wire in the harness that near the edge was still look good? All you did was just re wrap the harness and keep it from heat then the problem goes away?

Did you get a response for this? I have a misfire and after further inspection I have narrowed it down to the wiring harness. It's not in horrible shape so I'm debating on replacing it with a new one while they are still available or doing a quick fix.

 

[timchen]

Did you get a response for this? I have a misfire and after further inspection I have narrowed it down to the wiring harness. It's not in horrible shape so I'm debating on replacing it with a new one while they are still available or doing a quick fix.

What’s your symptoms?

 

[adamgunn]

What’s your symptoms?

It started as a P0305 running rough at idle then inspected the plugs, wires, distributor, etc and all was good so I cleared it and then it came back as a P0301 and now everytime I clear it the P0301 comes back. If I move the harness around the the EGR it will cause other cylinders to misfire, thats why I think its the harness.