I have an 88 Vert. that has a T2 conversion done and I have a problem. The car is running, but the idiot lights are all on, the gas , oil and temp gages are not working. A busser is on all the time the engine is running. I have checked the FSQ to find my problem. I must be not looking in the right place or I do not understand what is being said because I can not figure out what to do. We had a complete 1987 T2 to pull the parts from and used the T2 harness and computer. Any help would be appreciated.
One other thing the O2 sensors wire is broken off. I only see tow possible wires to connect to to one is a small two wire plug and one is an shielded wire neither of them is like the wire on the sensor(see photo). Any help would be greatly appreciated.
Thanks
Sheldon
Any one in the Prescott, AZ area??

 

First of all, using the TII harness is the hard way to do it. The NA harness converts over very easily.

The things you need to consider now are the connections between the ecu and the dash (front harness), and the connector on the back of the alternator. NAs & TIIs have this plug on different harnesses (engine management vs. engine harness)

I started to comb through the piles of TII swap threads looking for some in depth posts that detail it all out for you, but ran out of time. There are so many it's rediculous. Do a title search for "swap" for posts by a user named "Hailers". There are some very helpful ones that will detail out all the wiring problems.

 

Thanks for the help. I now have my idit lights working right. I still need some help in figuring out what my O2 sensor hooks up to. The was broken or cut when I got the car and I'm not sure what to hook it to. I have included a photo of two possable wires to conect to. One is a plug and one is a shealded wire. Any thoughts.
Thanks
Sheldon

 

That green plug is supposed to go to the water thermosensor on the back of the water pump housing. It's important that it is hooked up.

I don't recognize the other chopped off wires in the pic.

The O2 sensor wire comes off of the wiring harness near the primary fuel injectors, and is supposed to come out near the firewall & under the upper intake manifold. It's a single black wire, with a tan colored square plug.

 

Here's an active thread in the 2nd gen tech section w/ plenty of wiring info about using the TII harness with a turbo swap: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/need-advice-wiring-829592/

 

i think I have fixed all of my wiring problems now except for the O2 sensor. I forund a post once that said to just conect it to ECU wiring but I did not print it out at the time now I can not find it again. My O2 sensor wire was broken off and I can not find where it splice it to. Any advice??
Thanks
Sheldon

 

FSM wiring diagrams, page 50-25. The O2 sensor connects to the ECU at pin 2D, and the wire color is G/Y (green/yellow).

Look near the injector wiring, or just cut it at the ECU connector & run a new wire into the engine bay.

 

Thanks for the help
Sheldon

 

I have the harness from my engine that goes through the fire wall on the Pass. side. I'm looking at the yellow 18 pin plug pin 2D is a black wire not GY(see photo's). All of the other wire color codes are right. This way a JDM engine and harrness. I do find a G/Y wire in the car pluged in to the ECU F31(f) harrness. If you have any thoughts please let me know,
Thanks
Sheldon

 

The wiring diagram is kind of sketchy for the O2 sensor. It shows a black wire "connected" to pin 2D through the G/Y wire. I put it in quotes because it has a dashed line for some reason. I couldn't find an explanation.

I also know that on my S4 NA EM harness, the O2 sensor wire is black where it plugs into the sensor itself, so it's possible it's just a black wire the whole way. Whatever that black wire on the front harness plug is, it's not related. The O2 sensor circuit is strictly between the ECU & the EM harness. Give it a shot, then backprobe pin 2D, as per the FSM tests in the fuel & emissions section. It should have ~0.1 - 1.0 V on that wire if it's hooked up properly.

 

i want to thank you again for your help with my wiring problems. It looks like I have them working now. My problem is the car ran great before now it is running like crap and heavy black smoke. I did desmog the engine while I had it apart to work on the wiring. I'm sure that it is something I fergot to hook up. Any ideas??
Thanks
Sheldon