A wire is broken

1987 HONDA CIVIC
340 MILES
Avatar
LP23601
  • MEMBER
  • 13 POSTS
I have an 1987 Honda Civic stationwagon, manual trany, 1.5L engine. When I was doing some clutch/transmission work I broke/cut one wire by accident. That wire is in a cable that contains 4 separate wires (four wires wrapped by plastic tape), two go to a thermosensor right beneath the distributor, one goes to a temperature gauge beneath the distributor too. The last broken one I just can figure out where it should go. I looked everything in it is radius and can't find anywhere it can attach to.

The difference now than before is that the idle is quite rough. I have to adjusted the idle, increase a lot in order to keep it at around 1500 RPM, versus 750 before. Even though the idle goes up and down quite often that some time it dies when idle. Other than that the car seems fine.

Hope someone can answer my question.
Oct 21, 2011 at 7:18 PM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
One wire, or four were broken/cut? I've attached a schematic that should help. If not, please let me know and I'll look for another one.
Image (Click to enlarge)
Attached Media
Oct 25, 2011 at 10:39 PM
Avatar
LP23601
  • MEMBER
  • 13 POSTS
Thank you for the reply.
Several corrections.
1. the car has 340K miles.
2. the cable contains 5 wires instead 4. one goes to temperature gauge, two go to a thermosensor, another one goes to the oxygen sensor. The last one is cut. Looked everything within the perimeter of the wire and can't find anything.
My apologies for the error.

That wire is cut with bare copper exposed. The other end should be attached to somewhere but I can't find it. I looked oil pressure gauge and the other coolant themosensor and they are all well connected, and they are all connected by another cable anyway.

Thanks for the diagram. However it is so small that I can't read it.

Thanks much
Oct 26, 2011 at 11:13 AM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
Can you download the image to your computer and view it with Windows Photo Viewer? Once you open it with Viewer (right click and Preview) use the zoom feature to expand it. Let me know if that doesn't work. I'll see what I can do with Photoshop to make it bigger.
Oct 26, 2011 at 2:07 PM
Avatar
LP23601
  • MEMBER
  • 13 POSTS
It was scanned in small size or low resolution so even I enlarge it I still can't see it.
Oct 27, 2011 at 7:10 AM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
Ok. I opened in Photoshop and can zoom to almost unlimited levels. I just doubled its size. Try that.
Image (Click to enlarge)
Attached Media
Oct 27, 2011 at 1:24 PM
Avatar
KHLOW2008
  • ✓Experienced Mechanic
  • 41,812 POSTS
What is the color of the wire?
Oct 29, 2011 at 7:24 PM
Avatar
LP23601
  • MEMBER
  • 13 POSTS
It seems like my previous post got lost. I stated that I can see the diagram, but just not the text.

Attached is a picture of 5 wires.

The top one is the one that is broken. It is more like black/light brown, or black/orange.

The second one from the top goes to the oxygen sensor.

The third one goes to a temperature gauge

The fourth and the fifth one go to a thermosensor. The thermosensor has two terminals.

Thanks much.
Image (Click to enlarge)
Attached Media
Oct 30, 2011 at 6:41 PM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
In section B9 I see a brown and black wire that goes to the throttle angle sensor.
Section C9 one to the atmospheric pressure sensor, tying to the coolant temp sensor and pin C12 of the ECM.
D9 to the emission control box and pin c12 of the ECM.
E6 to ground, tying to an inductive pickup at the TDC position sensor and pin A14 on the ECM.
All of these also tie to the intake temperature sensor as well.

It appears that it may be a central ground wire.
Oct 30, 2011 at 7:52 PM
Avatar
LP23601
  • MEMBER
  • 13 POSTS
Thanks much for your reply. You are probably right. It is a ground wire. That is the reason I can't find the other end of the wire anywhere. The wire end probably had a terminal connected to a screw somewhere, then broke and fell somewhere when I was working on the transmission.

Just out of my curiosity. My car is a carburated car. You mentioned throttle angle sensor which only applies to fuel inject car, or Honda called it PGM-FI system at that time. Should we take another look?

Thanks.
Oct 31, 2011 at 10:12 AM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
Brown and black still shows up as ground for the carbureted 1500 and 1300 engines. Between the blue/white and white wires at one end of the Emission Control Module, which appears to be inductively tied to the O2 sensor wire.
Oct 31, 2011 at 3:10 PM
Avatar
LP23601
  • MEMBER
  • 13 POSTS
yes, it works now. It runs as normal as it used to. I will go at least another 100K on top of 340K now.

Thanks very much.
Nov 6, 2011 at 11:20 AM
Avatar
RIVERMIKERAT
  • ✓Experienced Mechanic
  • 6,106 POSTS
My pleasure. Happy to help.
Nov 6, 2011 at 8:00 PM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle