Disconnected wire from Exhaust Manifold [Archive] - El Camino Central Forum : Chevrolet El Camino Forums

: Disconnected wire from Exhaust Manifold


arkay
01-08-2004, 01:28 PM
While messing around with carb and battery today, I notice a sensor in the driver side exhaust manifold with a disconnected (broken off) wire. I found another wire coming out of the dash the was wrapped around the wiper to keep it clear.

I wonder if the wire from the dash goes to the sensor? What is the sensor and why would it go to the dash?

87ElCamino
01-08-2004, 03:29 PM
The sensor in the exhaust manifold may be an oxygen sensor. But I'm sure that 79's didn't have an oxygen sensor. Maybe the manifold was changed.

The wire wrapped around the wiper may be for the underhood light. What color is it?

Gozer
01-08-2004, 04:07 PM
Ummm - actually the 1979 wiring diagram (page 1) ( http://elcaminocentral.com/articles/wiring/811.gif ) does show an oxygen sensor, connected to a purple wire that leads to position 9 on the ECM connector...

arkay
01-08-2004, 05:03 PM
Ummm - actually the 1979 wiring diagram (page 1) ( http://elcaminocentral.com/articles/wiring/811.gif ) does show an oxygen sensor, connected to a purple wire that leads to position 9 on the ECM connector...

Thanks for the wiring diagram. I don't think my V-8 has a ECM connector. It was hard to read but I thing the drawing was for a V-6. Check the note at the top of the ECM connector.

The wire in my car is black and it goes through the firewall with the cable running to the cruise control unit.

arkay
01-08-2004, 05:04 PM
The sensor in the exhaust manifold may be an oxygen sensor. But I'm sure that 79's didn't have an oxygen sensor. Maybe the manifold was changed.

The wire wrapped around the wiper may be for the underhood light. What color is it?

Mine does not have an underhood light....somebody may have removed ti. The wire is black and it goes through the firewall with the cable running to the cruise control unit.

87ElCamino
01-08-2004, 05:18 PM
Ummm...that schematic is for the 231ci V6 with the California C4 system. (Computer Controlled Catalytic Convertor). It was only available in California, and only came on the 231ci V6. The other 79 engines did not have an ECM or an oxygen sensor.

87ElCamino
01-08-2004, 05:23 PM
The wire is black...
The only black wires in your Elky are for grounds. GM did not use black wires for anything other than ground. Maybe a previous owner installed it.

arkay
01-08-2004, 05:23 PM
The other 79 engines did not have an ECM or an oxygen sensor.

My 79 was deliverd NEW to my father-in-law in Birmingham, AL and was never near CA. It has a 305 V-8 with something sticking out of the driver side exhause manifold with a pig tail black wire about 1/2 " long sticking out.

acauth1
01-08-2004, 06:04 PM
Here is your photo...looks like an 02 sensor to me, odd on a 79 305



http://elcaminocentral.com/articles/DCP_0889.jpg

87ElCamino
01-09-2004, 04:55 AM
...looks like an 02 sensor to me, odd on a 79 305
That's because it's not a 79 manifold! Look at the plug for the AIR tube. The original manifold has probably been replaced with a newer one and the O2 sensor was left in it.

http://elcaminocentral.com/users/elcamino/pics/DCP_0889.jpg

acauth1
01-09-2004, 06:58 AM
Doh! :oops:

Vewy vewy observant!

arkay
01-09-2004, 07:11 AM
That's because it's not a 79 manifold! Look at the plug for the AIR tube. The original manifold has probably been replaced with a newer one and the O2 sensor was left in it.

http://elcaminocentral.com/users/elcamino/pics/DCP_0889.jpg

I recall my father-in-law saying he had to have a timing chain replaced and something tells me the shop had some trouble with the manifold and probably had to replace it with one they had that would fit.

Problem solved..... I will not worry about the O2 sensor that is not hooked up. End of long shaggy dog story. Thans for all of the help.

Dick

87ElCamino
01-09-2004, 08:20 AM
Vewy vewy observant!
Elementary my dear Watson! Like Sherlock Holmes, my fame rests on my remarkable powers of observation and my extraordinary deductive reasoning ability. :rolleyes:

What about that black wire Dick?

arkay
01-09-2004, 10:30 AM
What about that black wire Dick?

I am clueless on the purpose of the black wire coming from the the dash to the engine aea via the cable going to the cruise control. The only reason from bringing it up was the O2 sensor also had a black wire. I am not going to worry about te black wire.

acauth1
01-09-2004, 10:34 AM
Has to be something added aftermarket, only thing coming out the speedo cable grommet should be the cable.