Hello,
Currently I have an early style TT motor with a 1996 JWT computer and I asked Z1 what the difference is between harnesses for 1996 and the pre-1996 and its apparently completely different. I understand there is OBDII on 1996 and extra o2 sensors, different cams but obviously not in my case since my motor is early. I am at a point where I need to make a decision on continuing down this path. I am in Alaska and don't have access to different year cars, so I need to work with what I have. The body is a NA manual 1996 slick top. I love that there is already a better rear differential and no HICAS.

The problem is every mod I want to do is running into issues making sure its compatible with 96 computer and early motor. Right now I can get a pair of built 40P heads from a guy for a smokin' deal and they have JWT cams S1 100 mild w/ heavy duty valve springs built professionally. Is there a way to get an earlier computer in the car and stop all this 1996 B.S. or....will I run into major issues putting an early computer in a 1996 car. I don't need OBDII connector since I have the Conzult Diagnostic connector.

If OBD2 isn't mandated by your state (for inspection purposes) your best bet and probably cheapest option would be to get a new OBD1 harness and ECU, the ECUs can be had for cheap, the harness should be new.

Sounds good and that is the direction I am going. I have a newish EFI harness pre-96, 40P heads from a 1995 with JWT 100 mild cams completely rebuilt with 2000 miles on them. Also a JWT 1995 computer that is getting tuned for my 615cc nismo injectors, Dual pop. Keeping turbos, intercoolers, and exhuast stock for now. Will pull engine replace the heads, harness and ecu. I am looking at diagrams in the FSM and I see there is a difference that may hang me up though. There is a connector on the 1996 near the ECU that goes to the main harness and controls the rear o2 sensors, GST connector (OBDii), and a few wires go to the fuel pump. This connector is not present on pre-96. There is just a resistor there. I doubt any of that will be a problem except the fuel pump. I may have to somehow figure out a way to get the 1996 fuel pump wired to the 1995 harness. Anyone out there have suggestions or have run into this snag with a 1996 swap to pre-96 ecu?[img] I should clarify that there are two connectors that connect to the main harness in the 1996 but only one in the pre-96. I dont for see any problems with the one that is present in pre-96.

Looks like the Fuel Pump Control module doesn't really do a lot anyways according to this website.https://www.lojkits.com/blogs/the-loj-c ... -remove-it. At the worse case scenario I can remove the FPCM. Maybe I answered my own question. M94 is the connector in question if you look in the 1996 FSM. Page EC-262 is the reference to the FPCM.