VX swap questions

[Carwhisperer]

I have a 1974 Honda Civic which I made AWD by transplanting it onto a shortened 1989 Civic RT4WD floorpan/firewall (OBD-0 chassis). I've driven it over 100K miles since the transplant, with two different engines. Right now it is running a 1994 OBD-1 d15b from a JDM civic. I only get 30 mpg, which is a disappointment. I used to get 31-32 with the original non-vtec d16a6.

I picked up a cheap VX (d15z1?) motor from a guy who swapped it out for more power. What is needed to get the VX up and running in stock form? I've already got an OBD-1 jumper harness, I'm running an OBD-1 P28 ECU now. I've got the 4 wire O2 sensor. I've heard there is some component that needs to go on the firewall, or something, that is specific to the VX. I don't yet have an ECU.
Brian

[SVOboy]

A p28 and 4-wire isn't going to work for the car, unless you're planning to run california emissions, in which case you'll probably still need a cali vx ecu since I don't think anyone has dumped the rom for the cali vx yet. I would pick up a p07 and ntk/ngk 5wire or the swap really won't be worth it. You'll also need the additional wiring for the vx and the EGR controls.

[Carwhisperer]

Originally Posted by SVOboy

A p28 and 4-wire isn't going to work for the car, unless you're planning to run california emissions, in which case you'll probably still need a cali vx ecu since I don't think anyone has dumped the rom for the cali vx yet. I would pick up a p07 and ntk/ngk 5wire or the swap really won't be worth it. You'll also need the additional wiring for the vx and the EGR controls.

I meant that I have a 5 wire, not 4. My mistake. What extra wiring? Are you sure the VX has an EGR? Is the P07 the stock ECU? Is there a difference in the long block for a CA VX vs. 49 state VX? Or is it all external?

[SVOboy]

Extra wiring would be vtec, egr, 5 wire o2, I'm not sure if there's any besides that if you are already running mpfi.

I'm sure it has egr, I can show you a picture of the egr valve on my engine if you want me to.

P07 is the stock ECU

The differences are just the o2 and computer.

[Carwhisperer]

I'm already running OBD-1 vtec so I think it is just the 5 wire and the EGR, right?

[MadisonMPG]

that is a strange car

[SVOboy]

Originally Posted by Carwhisperer

I'm already running OBD-1 vtec so I think it is just the 5 wire and the EGR, right?

Probably, yes. I forget from when I did the swap but that seems about right