Help, Poorly Running 80

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fj40fax said:
Thanks Proven!

I will print this out and give it to my mechanic tonight. I am towing it down there after work tonight. I wish I could habd him my FSM too. Gotta order one of those, wonder if CD is still in today?
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All this and you're not going to take the 1 minute to look behind the glove box. :confused: :confused: :confused:

-B-
 
To side with Beowulf...he might be the bluntest guy on these boards, but after reading TONS of his posts he is very familiar with the 80. Please humor his idea, he is a pretty sharp cat.
 
I am if I can get home in time before my ride gets there. Seriously, i'll pull it asap before it goes under the knife at the shop. Thanks, Beowulf!
 
Pulled the glove box, looked around with a mirror. I can see where the harness had contacted the brace, but I could not see one bit of copper wire. Rubbed where the tiny dents were and could see no rub through. It's at the shop to tear into the harness by the EGR. I will post up results in a day or 2.

Thanks,
Fax
 
It is over at the shop and he made quick work of the wiring harness.

One red and balck wire was fried all the way through, one was really bad so it got spliced also. A couple others had some bad insulation so they just got some tape.

It is now awaiting me getting some heat shield. I am thinking header wrap and some heat proof Zip ties.

Thanks for all the help, runs like a charm now.

The red plug in the top pic is stuck in the EGR so it would run, but it makes a nice frame of reference too.

Fax
Harness1.webp
Harness2.webp
 
Good to hear that you've got it fixed. Dan nailed it in post #6.

You can get this stuff at Summit or Jegs or most any speed shop.

89314002.jpg


-B-
 
There is no questioning the master. Most of this was making sure it wasn't something else before I took it in to rip into the harness. When I asked the mechanic he said it would have taken him a loooong time to figure out exactly where the prob was. I probably saved a few hundred to a thousand in labor because of this board! I love cruiserheads! I hope this thread will be of use to others experiencing similar problems. This really is a 1-1.5 banana job and I could have done it if I had the time, but I'll make more at work than I will under the hood so the trade off was good for me.

I took over some header wrap, nice thick asbestos stuff. I also took over a shiny starter shield that should give the exact same effect as the above stuff, but he can lay it on nice and thick. The starter shield came with come clamps to hold it down nicely.

Thanks again for all the help!!!

Fax
 
fj40fax said:
This really is a 1-1.5 banana job and I could have done it if I had the time ...
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Well Fax, you have to admit that we tried our best to get you to get on top of the engine and take a look at that harness 11 days ago. After you put on the new intake hose that was the only other thing that has routinely caused the symptoms you were reporting.

It's done now and there is a very high probability that this is a long term fix if you got the right heat tape.

Asbestos wrap? ? ? ? I hope not. :frown:

-B-
 
Asbestos looking? Pretty standard header wrap. I'll post a pic of the finished product, should be nice and shiny.

The 11 days was me taking my time making sure it wasn't something else to minimize the time in the shop. After replacing all the PM stuff in the beginning, I only spent maybe an hour or two on the rig. If I had this thread to reference when I started I would have torn into the harness right when Dan suggested it in post 6. I happened to have the time and a spare vehicle to take my time with the hunt. If this was someone's DD it would have been a very different situation, but with the help of this thread they can have it figured out in a couple hours.
 
Oh, I'm also going to put some protection on the edge down by the glove box too. It should keep that area safe for quite a while.

Fax
 
If anyone else has to do this, take the hood off! You can just stand on a crate and reach this area easily. Also unbolt the harness protector from the fire wall, it will give you plenty of slack to get to the wires you need.

Fax
 
So I have read through this post (and similar posts) my truck is acting exactly the same as fj40fax's. I replaced the plugs, wires, cap etc. Truck started fine, had a nice idle and then after a short drive it reverted back to poor idle, black sputters from exhaust, strong smell of fuel... So I tore up the heat sheilding and inspected the wire harness noted by CDan and Beo. The heat sheilding was a little charred so I expected the worse, but once inspected I found nothing wrong with it. So I am lost, where to next?
 
Is your's throwing any codes? That was the key for knowing mine was in the harness. My wire that went to the 1,2, and 3 injectors was broken right above the red square on the wiring diagram above.
 
My bet is that it is the harness, and you are getting intermittent contact at one of those wires. That means it will be much harder to find. Jiggle the harness with it running and see if you can get it to run rough. Inspect all your wires very carefully as your insulation could be intact, but the wire broken inside like a broken arm. Bend them and look for hard angles where the wire inside could be broken. Hope u find it soon.
 
Ruadhrigh said:
So I have read through this post (and similar posts) my truck is acting exactly the same as fj40fax's. I replaced the plugs, wires, cap etc. Truck started fine, had a nice idle and then after a short drive it reverted back to poor idle, black sputters from exhaust, strong smell of fuel... So I tore up the heat sheilding and inspected the wire harness noted by CDan and Beo. The heat sheilding was a little charred so I expected the worse, but once inspected I found nothing wrong with it. So I am lost, where to next?
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if it happens after the engine is warmed up, it could be the FPR. what year is your truck? if its the 3FE it is a 20 minute fix if that, cant hurt to do it...
 
Gonna need to tell us about codes you are seeing. very few engines make that much racket without telling you something.

Thank god for OBD.
 
I had a code saying Cylinder 5 misfire, and insufficient EGR flow... I disconnected the battery when I did the distributor cap (made it easier to get to) I didn't get any codes after I replaced all the plugs etc. The harness looked good to me but I didn't jiggle it while it was running. Right now I have the truck pretty torn up, I cleaned the EGR with some brake cleaner, I'll re-assemble tomorrow and see what happens. The guy at Autozone was trying to tell me that the cylinder misfire and the EGR were realted, but I don't see it.
 
Ruadhrigh said:
a buddy has suggested that the injector could be flooding the cylinder because of an arc. any thoughts on that?
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Rory,
If you have a problem in the wiring harness (2 problem locations) then it could cause several symptoms including a "stuck" injector and a "dead" injector. It just depends on which wires are shorted or broken. The most common problem is the area where the engine wiring harness passes the EGR valve. The next area is where the engine wiring harness enters the cabin and the area right by the ECM. Your ECM is behind the glove box (2 phillips screws and you can see it.) Check both areas carefully and wiggle the harness while the engine is running.

I don't think the EGR code is related to the rough engine. I have a spare EGR modulator if you want to give that a try. There are a lot of posts on the "Insufficient EGR flow" (aka P0401 in OBD-II trucks.) I also have an OBD-II scanner so let me know if you need it.

How does the intake tube look?

-B-
 
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