So I yanked my distributor on my 87 GTA. I have had a real sneaky suspicion that my Pickup was going bad. I started to pull the distributor up and saw a lone green wire coming off of the base of the distributor through one of the vent screen holes (had been removed). Upon further inspection this green wire was soldered onto the green wire of the pickup connector. (horribly too)

WTF is the green wire on the pickup connector? I am puzzled as to why someone would solder a wire and then run it out of the distributor back into the wireing harneess that goes over the heater box into the passenger side cabin. I can tell it is NOT original.

Has anyone heard of people doing this for some reason? Could it be a tach? mabey a kill switch? My car has no aftermarket gauges other than a tranny temp. everything else is stock, I have the digital gauges option. My tach is working. I have heard the previous owner said that there was a very nice alarm system installed by the owner before him, but was disabled.



Info wanted...

 

That would yield a VR signal, well, half of one.


The only thing I could think of would be an aftermarket ECM of some sort. Anything else wouldn't really run off of the VR signal, as it needs to be converted to a hall-type (square wave) before it is really useful.

 

Hmm, just plain crazy! The car as far as I know is stock.. Arggg now I am gonna have to trace the damn wire just so I know what It is..

Now a question is, since this wire was added to the connection at the pickup, would this cause a big change in what the ignition module would see as far as a signal? The reason I ask is this would add considerable resistance to the signals reading would it not?

I asked the previous owner about the wire, he had never touched the distributor other than cap and rotor. He has had it since 2003 so it must have been there for some time.

 

Vr sensors work by using a fixed resistor. The sensor generates a small current when the tooth approaches, which goes inverse as the tooth leaves. When the signal goes from positive to negative voltage, the tooth is aligned with the sensor. This is how the module knows the position of the distributor.

The Ignition module measures the voltages across the resistor. As long as the wire is not shorted, the only thing I can see it doing is channeling electrical noise into the VR signal. A new pickup is 17 dollars... you might try removing the wire and if that doesn't help, replacing the pickup, being as it is so cheap.

 

I am for sure replacing the pickup since it is so important and of course super cheap. I will install in without that added external wire and see how it works. I hope this solves my crazy ignition problems.

I also noticed that the sheathing was cut clean to the core just after the back of the connector. So who knows.. I will get it replaced tomorrow morning and post an update.

 

Got the pickup coil in and replaced. after playing with the timing for a bit, got it right at 6 degrees.

Starts better than before and the green wire thing must be a wire to the old alarm. I can only think it is a ground that gets enabled if the alarm was to think the car was being stolen. Regardless I don't need it so I tucked it back into the harness.