OK, I've read just about everything on the topic by doing multiple searches. I'm changing out the CFI for a carb. I removed as much of the computer wiring as I could without cutting anything (as others here have suggested). I also referred to about four different manuals to try to track down my questions. A few wires had to be cut as I could not find the end of them... there must be a mile of wiring involved with the computer! Specifically these wires:
1. Oil Pressure Sensor had three wires to it, a red wire that goes to the Fuel Pump relay (still connected), an orange wire that the manuals say is supposed to go to the battery(had to cut it, but left about five feed wire), and a tan wire that I cannot figure out what it is or where it goes (ditto on cutting it about 5' away from the sensor). Anyone know about the tan wire?
2. Fuel Pump Relay has five wires leading off it - a red wire that goes to the Oil Pressure Sensor, another red wire that the manuals say goes to the fuse box/engine harness (had to cut it, left it long), an orange wire that the manuals say goes to the battery (another cut...), a black/white wire that is supposed to be grounded (I think... it's also cut long)), and a green/white wire that is supposed to go to the ECM (another cut wire). Can anyone confirm the black/white wire and the green/white wire connections? Is the red wire to the fuse box switched or always hot?
3. I also had to cut three wires that disappeared behind the engine on the backside of the distributor - a purple wire, a light blue wire, and a tan/black wire. The only wires in the manuals' wiring diagrams that match these are: purple to O2 sensor, light blue to either power steering a/c cutoff or 4th gear discrete (auto trans), and tan/black to ECM converter control solenoid or HEI bypass. Any idea on these three wires? Not real sure about the last two since different books had different connections for those colored wires...
4. Finally, I'd like to rewire all the stuff coming directly off the battery, anyone know what size fusible link to get for that?
Thanks,
Rob

 

Ops,

My best guesses, in no particular order:

The tan wire at the oil pressure switch is for the oil pressure gauge or idiot lamp;

For the fuel pump relay, the orange wire is constant battery voltage through the ECM fuse under the hood. The green/white is from the ECM relay driver to operate the relay coil, and the black/white is chassis ground. The larger red wire is the fuel pump power lead that parallels the wire from the oil pressure switch and runs back to the tank. The smaller red wire is switched and should connect to the GAGE or F/P fuse circuit.

If the tan/black and purple wires are in different parts of the harness, the tan/black wire could be for the EST bypass control. If this wire does not get reconnected, you will have no ignition advance. If you are converting to a vacuum/centrifugal advance distributor, this is not a real problem. the purple wire would likely then be for the oxygen sensor.

If the tan/black and purple wire are in the same harness/connector, they are likely for the torque converter clutch on the transmission.

As for the fusible links, to control at about 60A, use a 6" length of AWG 12, and 19 strand would be best for durability.

 

Thanks for the help Vader!
I should've figured out the tan wire on the oil pressure switch... guess my mind was too full of wires to see the obvious!
I'll have to go back and check on the other wires. I think both red wires on the fuel pump relay were the same size, but I'll check on that. Sounds like I have to find where the second red wire connects, especially if it runs back to the pump itself (or does it run to the pump thru the fuse box?).
I am switching the distributor to a non-computer one so I guess I won't need the green/white wire and the tan/black wire. Ditto for the purple, O2 sensor wire.
Since I'm ditching the computer, I understand I'll need a kit like the ones to install a 700R4 in a street rod. So... I'm guessing I won't need the purple wire either if I get one of these trans kits.
Thanks again for the help!!!
Rob

 

ops32

are you going to be switching your fuel tank sending unit ??? if you are let me know, I'm adding tpi to my carbed 82 and need a efi sending unit, also ops32 ... I will trade you my carbed cold air setup for your cfi stuff.