D16A6 from automatic into wagon DX manual

udubrx7udubrx7 Senior Wagonist
in Engine & Drivetrain
I've got a friend who is giving me a d16a6 out of his automatic 1990 civic ex. I can get any parts I need from the car from him (engine harness/ecu/etc), but I'm not sure about everything working correctly since my car has a manual transmission. I'm going to swap the MT flywheel onto the motor, but I doubt I can use my dpfi 5spd ecu with the pgm-fi system on the d16.

I read about doing the conversion inside the d16s auto ecu so that you dont get the error code for auto trans lockup or whatever it is, and I'm sure I could do that pretty easily, BUT:

Will the D16s automatic VSS screw into my manual trans with no problem, or do I need to splice in the one from my 5spd?

Will any performance related problems arise from using the auto ECU?

I've also heard some things about having to replace either the throttle body or whole intake manifold..... say it ain't so!

Could I use any other EF 5spd ECUs that utilize mpfi, or perhaps one from an integra or something? I've heard that some integra ECUs are compatible and offer better fuel maps and a higher rev limit....


thanks for your help!

Tom

Comments

  • curtcurt Wagonist
    going to have to do a dpfi to mpfi swap as well.
  • fettcolsfettcols Wagonist
    If I'm not mistaken, the 1990 ex didn't have a VSS, it should have the same cable speedo set up as your DX. I believe the OBD1 cars have the VSS.

    At least it's that way with the manual transmission cars. I guess automatics could be different but I would really be surprised.
  • wagodizzlewagodizzle Council Member and EDM expert
    the EX sedan had basically the same tranny as the DX wagon. so no VSS... just the cable.


    so i think
  • 85civicwagon85civicwagon Band Wagon
    heres the dpfi to mpfi swap link
    http://hondacrx881.tripod.com/mpfiswap.html 8)
  • udubrx7udubrx7 Senior Wagonist
    well I'm finally going to be getting around to doing this soon..... just wanted to get a few things straight though....

    Since I'm going to have the whole EX available to me, can't I just swap all of the wiring harness and everything from the EX into my DX, and just disregard whichever plugs are for the auto tranny that I'm not using anymore? That's assuming I had bought a 5spd ecu also.

    if anybody can clear that up for me that would be great!

    thanks
  • White&NerdyWhite&Nerdy Senior Wagonist
    You can make it run, but that doesn't mean it won't throw any codes. The wiring's going to be the fun part, between the auto/manual thing and the DPFI to MPFI swap. Fortunately the swap is well documented. As for the ECU, you could look for one from a car that had a manual D16A6. Shouldn't be hard to find, since many have taken their Civic/CRX Si and dropped a bigger motor into it, meaning there should be a lot of stock D16A6 manual ECUs available. I don't know anything about using an Integra ECU on a D16A6.
  • wagodizzlewagodizzle Council Member and EDM expert
    i have a spare manual D16A6 ECU sitting around... its the PM6
  • yellowmikebikeyellowmikebike Wagonist
    The intake manifold, fast idle valve and throttle body are different on AT vs MT. The AT's idle @ a higher RPM than MT's do. Use your speedo cable, the AT's cable and attachment/gear are different. Of course the AT and 4WD 5-dr cars also had power steering and the 2WD MT ones didn't, the EX will have power steering, but you can just remove the pump.
  • fettcolsfettcols Wagonist
    If the ecu is a PS9 I'll trade you a PM6 for it.
  • udubrx7udubrx7 Senior Wagonist
    Cool I'm glad it will idle a little higher since its from an auto - ive got poly inserts in the torque mounts and at 650rpm theres too much vibration anyways.

    It is a ps9 ecu, I don't think I want to get rid of it though. It's only going to throw a CEL for the auto tranny lockup solenoid, and I'm willing to deal with that until I can get a z6 head and make this baby run one wire vtec!

    And if anyone is curious (took me a while to find this out):

    You don't have to do the mpfi swap if you also swap over the cabin harness from the mpfi car. But most people don't have that available to them, or would rather not do that cause it'd be a bitch. The real reason to modify a DX harness instead of using the Si or EX harness is because of the short section that runs from the big plug by the fuse box to the ECU. The big plugs aren't the same for the DX and Si, and that section of harness doesn't carry the wires for the other two fuel injectors.

    Also, front door panels are definitely different in the EX - they fit but I have to slam my door to get it to latch because the trim doesnt match up with the dash. The front seats also have different shaped sliders (you would HAVE to use the ones from your wagon to install EX seats), and the bracket for the automatic seatbelt is slightly different. So - to put EX seats into a wagon you need: wagon seat rails, EX auto seatbelt bracket installed on the wagon rails.
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