Not certain, but this swap should be pretty easy using a '94 - 95 VTEC ECU (P0A?) and the F22B2 distributor from the old engine, especially if the B2 intake manifold is swapped to the F23A1. Depending on the year of the F23 you may have to swap out the water outlet flange because later-23's (2000+) didn't have a Thermoswitch B. You'll have to run two wires from the ECU to the engine compartment to use VTEC: the VTEC solenoid valve (A4?), the VTEC pressure switch (D6?), and ground the other side of the solenoid to the engine. I've never done an OBD2 engine swap into an OBD1 car so that's why I'm not certain about the ECU and pin numbers. Maybe someone who's actually done that swap can chime in.

There's no place to mount the B2's ignition coil on the A1 so you'll have to jury rig something. I ended up using an old bicycle reflector mount, bent and drilled, to mount the coil:

 

I have already swap dizzy and intake manifold, so I think that takes care of some sensors, all I need now is to wire for the VTEC. I have the pinout schematics for OBD-1, what I don't have is the VTEC ECU. Can I mod my ECU to make it VTEC?

 

don't think so. And I would be surprised if your f22b ecu will run the f23a1 at all

 

No F23 engines had fan-switch-B. I had a 1998 (first year for F23) & there was only one fan switch.

 

An F22B1 ECU runs my F23A1 just fine. I believe an OBD1 VTEC ECU is a P0A-A01, originally installed in 94-95 EX manual trans Accords, would fill the bill. Wiring the VTEC is easy, especially with the engine/trans out of the car. Here's pic's of my half-assed wiring job:







I just ran the wires though an existing grommet near the heater valve, which also has the (red) wire for my amp going through it. I found the pics on ff-squad(dot)com excellent for adding/removing pins from the ECU plugs.

JimBlake: You're right. I was mistaking Thermoswitch B with the temp gauge sender. 2000-on (as I recall) didn't have a separate sender for the gauge but it does have a plug where the sender goes. OP: just pull the sender out of your old engine and put it where the plug is if you have a later model F23:

 

Helo


I have done this swap in my 4th gen prelude i kept my obd1 harness most things plugs up.needed to advance the distrbuttor andbrepositon sparkplug wires and a few minor adjust ment still in the progress.but i have the harness and ecu so am reconsidering putting them in to make it more simple and easier ...

 

The F22B ECU runs the F23A1 just fine, except no VTEC. As I recall, I ran the non-VTEC ECU for a couple of weeks before I was able to get ahold of VTEC ECU. Lots more torque after that was plugged in.