Ok, PAhonda, thank you for your help! I'm not sure that the problem is all in the engine compartment, such as 5 volts on the green/white wire, or if it could be some kooky business with the ECU or TCU. I will do more checking and research and decide my next course of action.

As I mentioned previously, dealing with the two computers was exceedingly cramped, and nearly impossible to do any reasonable probing of them. Are you familiar with a good way to make them well accessible without tearing things up in the process? If not, it might be well for me to start another thread on just that subject.

Thanks again!
Caduceus

 

The ECU and TCU are below a metal plate in the passenger footwell. You should be able to unbolt that plate to lift it up and and have some room.

Google 62SN700.pdf to find the 93 non-US manual I have. This manual doesn't exactly match some of the items you mentioned, but it will be close. For the IAC circuit, I'd unplug the ECU, then find the pin on the ECU with the same wire color to the IAC (and hopefully match the manual), then use the continuity (open/closed cicrcuit) on your volt meter and go through the rest of the pins for the ECU/TCU to see if that wire is shorted to another wire.

You should look at the connectors for the ECU and TCU to see if any corrosion is there. You can open the ECU and TCU to see if there is any corrosion inside.

Having a shop manual will help with the red/x wire that I'm not sure is connected correctly.

It can also help with the two chewed wires that are missing a home. I suspect that they go to somewhere nearby like the transmission. There has to be some sensor that is missing a connection in that general area.

A lot of this is detective work, but I don't have a good wiring diagram to give decent advice.

 

That sounds like a great idea for checking if there is continuity between the green/white wire and any others. I just bought a 1993 Accord Electrical Troubleshooting Manual on eBay, which I hope and think is just what I need.

 

I found out where the other end of this chewed connector is.



It is supposed to be connected to this sensor being pointed to with a phillips screwdriver. It's in the right side fender well, on the end of the automatic transmission.

Here is the sensor pulled out. Will someone please tell me what this is called, and what information it sends?
Thank you!

 

That is a sensor detecting rotation. I don't have a shop manual in front of me, but could be the main shaft or countershaft speed sensor. If you go to a site like hondapartsnow.com, you can identify which sensor it is.

 

Thanks, PAHonda!

 

The three wires for the VSS were cracked and shorting out on each other about five inches frm the sensor. I did not want to pull the engine harness out to repair them, and could not reach the bad areas with my strippers. I ended up running three new wires from where they came from, in front of the left side strut tower. Both the Coolant Temp Sensor and the Intake Air Sensor had about 5 volts on both of their wires, when one wire of each was supposed to be an ECU sensor ground. I snipped the bad wire on each of them, and ran a new ECU sensor ground wire to the connector by intercepting a good sensor ground and running a replacement wire for each.

For the Speed sensor with the chewed off wires shown in a picture above, I soldered new wires to the nubs and got that working again. I have a new sensor ordered to replace that one since I don't want to rely on my shady emergency soldering technique, using a propane torch and melting some of the plastic on the sensor and barbequing some of the wire insulation.

Now the engine starts much easier and that is very pleasing!