Laminate01

I have been searching forums and threads for several days now and have not found the exact information i am looking for. Every thread i find is very very similar but always something that throws it off. i am not swapping heads, i am not trying to upgrade to any crazy obd ****.

This is a 1990 civic hatchback DX 5sp manual with a D15B2 DPFI (PM5 ECU). all i want to do is take my stock d15b2 DPFI intake manifold and throttle body off, and swap it with a Y8 intake manifold, throttle body (tps) fuel rail, and fuel injectors, with as little modification as possible.

If i have to get a different ecu i will, but i have a PM5 in the car now, and a P28 or whatever the d16y8 ecu is laying in my garage. I have the manifold and fuel rail and injectors already. I dont want to buy any premade harnesses, i want to rewire whatever i can myself and modify whatever ecu i have if possible to make this work. i know how to work on honda D series i just am not familiar with different parts from different engines made in way different years all working together.

the physical swap itself is trivial, i need to know what ecu and or how to modify said ecu for the y8 intake/fuel rail/fuel injectors/TPS. i have seen many writeups on how to modify the pm6 to use a 88-91 civic si mpfi intake but that is not what i have nor what i want. i have the a 1997 manual y8. someone please kindly help or point me in the right direction. it would be very much appreciated.

24TEN

iTrader: (2)

Most write ups will state to use the PM6 ECU by default because it matches the OBD configuration of the car/engine. The PM5 ECU is not an option so don't even count on it working for a MPFI conversion. Generally speaking, a P28 is OBD1 and a P2P or whatever the D16Y8 ECU is designated is OBD2 (to go even further there is an OBD2A and OBD2B). If your intention is to stick with the ECU you already have then YOU MUST CONVERT OBD CONFIGURATIONS. Depending on OBD you'll need to add a sensor or 2 but it's doable. Also, because your engine is not VTEC you'll have a check engine light because the ECU you have will be looking for it. With that said, it's much simpler to just buy a PM6 ECU and be done with it or give in and buy the jumper harness that is specific to your setup.

A word of advice:
A wire is a wire, a pin is a pin. Don't let the term "OBD conversion" scare you. All you're really doing is changing the ECU plug and adding wiring where needed for addition sensors. The jumper harness just lets you skip the hard part of depinning and labeling all the wires at the ECU.

4drEF

Agreed ^^

If all you are switching is an intake manifold, then there is no reason to even consider going OBD1.

Do a DPFI to MPFI conversion and you are done. If you use the Y8 injectors, then you don't need an injector resistor box. You will need the Y8 injector harness clips.
you will also need a D16A6 distributor and D16A6 ECU (PM6). Take a look on google for different remedies for the throttle cable bracket. Flipping the Y8 bracket works, but there is a bracket you can get from an old Accord? or Prelude? that fits much better. Your idle might be a little weird because the Y8 handles idle control differently than older engines. not a big deal.

Laminate01

Thank you for the info and fast response guys, looks like im gonna research into that option and see if its worth spending the money. i also may just do with what i got for now and get pistons for the d16y8 and put it back together then swap it.