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F23A1 to H23A swap throwing Cel

Discussion in 'HYBRID -> BA-BB /CA-CD' started by lithiumus, Dec 15, 2006.

  1. lithiumus

    lithiumus New Member

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    Not a lot of update but I thought that this may be a significant one...

    I've sourced a JDM Honda PCD obd2b ECU. This is the closest matching OEM ECU for the H23A VTEC engine aside from the original (which I can't remember the code) Auto ECU...

    I'm going to try the PCD ECU and see if it does a good job running the H23A VTEC. The only thing lacking is that the PCD does not have IAB control. Worse comes to worse, if the PCD ECU works well, I might just wire up the IAB and link it to VTEC so whenever you are in VTEC, the IAB will open up.

    This does involve re-installing the secondary O2 sensor and uninstalling the AEM Wideband and re-installing the primary O2. I'll update on how this progresses. If all goes well, I'm going to try to pass emissions with the PCD ECU.

    BTW, the PCD ECU does NOT have an immobilizer. I see where the space it for the immobilizer board, but it's not installed.
     
  2. gus33

    gus33 New Member

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    lithiumus,
    I have recently purchased a JDM '99 Accord wagon H23A w/ auto trans. It has a PCF computer. This computer also operates the trans( 4 plugs, not 3). Based on your pictures, there is no immobilizer circuit board.I don't know if this info helps you or not, maybe you can help me. I need wiring diagrams for this setup. I am using this combo for an off-road only vehicle. Stock performance will be fine, I have most of the original wiring harness, the wiring from 1 plug was cut( I think it went to dash area) all others are intact. At a minimum I need pinouts for the ECU, but wiring diagrams for the '99 accord would be best.
    Since this was a JDM only motor, I havent had any luck with US accord wiring diagrams.

    Thanks,
    gus
     
  3. DESPAIN

    DESPAIN yep....mmhhm.......yep...

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    check the dates!!!
     
  4. GIN HISA 99

    GIN HISA 99 New Member

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    Lithiumus, Great thread! I have a 99 Accord LX auto that I am wanting to do this swap in, since my F23a block decided to crack with only 56k miles on it. I read the entire thread and it seems that it might just be a bolt in & plug in swap for me other than the driver's side motor mount that you mentioned. Did you ever find out exactly what your mechanic did with that? Is there any other info you can provide me before I dive into this project? Please let me tap into your hard earned knowledge and experiences and I thank you in advance for any help you can provide me!
     
  5. lithiumus

    lithiumus New Member

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    Hello, long time no check in for me but I'll stop by from time to time and give any info that I can. If you are putting this engine in a USDM car mainly is the ECU mismatch problem. This JDM engine does not have the crank sensor or crank angle sensor at the oil pump as the USDM engines do and instead all 3 sensors are located in the distributor.

    If you just plug the engine in, your ECU won't like it. Alternatively, if you have the original ECU, there is a high likelihood that you may be able to just plug the JDM ECU in and it will work just fine. There is one pin that you will need to relocate for the Fuel Pump Relay as the JDM and USDM basically are shifted over by one pin. I couldn't figure out for the longest time why none of the JDM ECUs would even fire up but now I know!

    gus33, if you PM me, I can try to help you map out wiring if I can. If only one of the OBD2B auto plugs are cut, I think you have most of the puzzle figured out and just need to confirm a few things to get it right.
     
  6. lithiumus

    lithiumus New Member

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    Just a quick update from me... I'm still using the AEM EMS with wideband and I still pass emissions but because it's my daily driver, I'm sick of always having to mess around to get things right. Good thing this winter has not been too cold so all the cold starts have been fine but I'm still running into stalling issues once in a while and I'm going back to stock as I have no desire to dyno tune my engine when a simple OEM ECU should be able to power it just fine for daily driving.

    PCF or PCD?
    I'm not sure which ECU will work best so I have the original JDM PCF auto tranny ECU as well as the JDM Euro-R PCD manual tranny ECU to try out. Obviously the PCF is ideal but the PCD might also work out nicely. I don't know if I'll be able to use the auto ECU in a manual car but I hope that it's not too tied into the tranny to make ignition and fuel decisions...

    Tricking the Auto ECU
    I'm going to wire up a relay to trick the ECU into thinking it's in "P" when the parking brake is up and in "D" when the parking brake is down. That's the best I can do, I can't provide all the speed signals from the tranny so I'm hoping that the simple "D" signal will allow it to engage the right fuel, ignition and VTEC capabilities. If not, I can always try the PCD ECU.

    IAB - Intake Air Bypass Valve
    The last and final issue is that this engine has IAB's like the Prelude and Integras. They are supposed to open up at higher RPMs and close at lower RPMs. The Accords don't have this and the original mechanic who did the swap pulled all those parts off and tossed them. I ended up getting all the OEM parts but I need to run a wire from the IABs to the ECU if I decide to use the PCF auto ECU.

    If I end up using the PCD ECU, that engine does not have IABs and instead uses a specific IABless intake manifold shared by the JDM Prelude Type S, JDM Euro R and the EDM Accord Type R. If that's the case, I may need to look for a Euro R IM or maybe get a Skunk2 Prelude IM. It's not a cost I want to bother with but I do want to get it to run properly.

    I only did a quick test with the PCD ECU and it fires up but since I had the wideband o2 sensor hooked up, it idled a bit funny. I'm pulling the AEM out this weekend and will try to use one of the JDM ECUs. I'll report back my findings.

    Intakes
    And if I hadn't mentioned this before, the Accord intake is much too small for the Prelude engine and if you couple an Accord intake to it using an adaptor, you'd be doing yourself an injustice by restricting the air inflow. I used an AEM Prelude CAI but the issue is that the mounting points are wrong. I had to come up with something to keep it stable and will probably build a bracket or try and see if a Prelude Type S intake will fit.

    Exhaust
    I think I owe this thread some pictures so I'll try to take some and post my final conclusions. I still don't know what I should do with my exhaust but I'll discuss it with my mechanic... I've got the OEM JDM headers but were cut welded directly to the Accord OEM Cat. That basically reduced the 2.5" diameter to 2.25". The rest is OEM Accord. I currently have an Accord V6 exhaust system which I may have my mechanic mate up with the JDM header and use the V6 Cat. That way, at least I'll put a flange back on the header so that it mates up to the V6 Cat properly and the rest of the system can be OEM V6. More to come plus some pictures I promise!
     
    Last edited: Jan 28, 2010
  7. d3r3k99lude

    d3r3k99lude New Member

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    h23a vtec

    i im runing in to a prob and im hoping u could help me i need wiring diegram to the h23a dizzy for cranck sensor plz help
     
  8. lithiumus

    lithiumus New Member

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    It's the same as the OBD1 dizzy where all the sensors are in the dizzy. Look up some 4th gen prelude service manuals. All the sensors are in the dizzy.
     
  9. lithiumus

    lithiumus New Member

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    Quick update since I'm here anyway...

    I've been running the PCD JDM Euro R ECU for several months now and it's working perfectly. Though I finally had the AEM setup quite stable, it was nice to go back to an OEM ECU and not having to worry about anything anymore. The only hurdle will be emissions but from I've seen and "smelled" so far, it looks pretty good and nothing is out of the ordinary.

    I'll eventually get around to hooking up the IAB and activating it when the VTEC comes on. Ideally it would be smoother if the IAB activated earlier but since the PCD ECU doesn't have provision for IAB, VTEC is the best way to activate it.

    I'm staying with the AEM intake. I've put my OEM intake back on and I feel a huge difference due to the smaller inlet.

    I'll eventually fix the exhaust and put a AV6 on there. I have all the parts, it's just low priority...
     
  10. H22A7

    H22A7 New Member

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    Is it possible to run the ECU without the HIC370 and without immobilliser functionality, with it completely removed or does it need a board in there just work regardless of whether or not you want/need immobiliser functionality?

    Thanks
     
  11. lithiumus

    lithiumus New Member

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    If you run the ECU without the immobilizer chip, it will start after 2 seconds in IG2 but once the car starts, a CEL will stay on the entire time. I'm not 100% sure what it does but I imagine that it will limit the performance or some functionality.
     
  12. 1slicvic

    1slicvic New Member

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    Jdm h23 in 2000 Prelude Auto Tranny Problem

    Recently did engine swap to Jdm H23 with auto H22 tranny but tranny does not come out of 1st gear, when it should shift it just slows down harder, trying to find out if H22 ecu needs to change or if this motor doesnt go with this tranny worked fine in H22.
     
  13. lithiumus

    lithiumus New Member

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    The only thing I can think of is that the various speed sensors are not wired correctly and the ECU isn't sensing the speed and not shifting as it should...
     
  14. stiv625

    stiv625 New Member

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    Great, great info Lithiumus. I'm sure it's helped a lot of people with this swap; I had some concerns dropping an H23A in my 96 Accord but I think this has pointed me in the right direction. Also love the info on the AEM (esp the emissions testing info), but I feel better knowing you ended up with a stock JDM ECU for a daily driver as this is the route I was hoping on going.
     
  15. iviaillet

    iviaillet New Member

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    I gained alot of information from this thread, thank you. I have a 2002 accord F23A4 and im swapping a 2000-01 H23A into it that I recently purchased from Hmotors, they recommend the PCB ECU which I believe you said will not run the H23A, but here in Mass inspection, they only plug into the DLC, no 5 gas or dyne, you said the PAA and the PCD ran similar before you mounted an external coil, so I was wondering if the PAA ECU would be able to run the H23A enough to clear all the codes with an external coil, I would love to find a PCD ECU but i'm not sure where to find them.

    What do you think about possibly swapping the USDM H22 oil pump and crank sensor, USDM H22 complete Intake manifold, distributor, and removing the immobilizer or possibly swapping it with my accord, the USDM route seems like it would pass inspection no problem, do you think the immobilizer chips are the same between 2001 USDM preludes and 2002 USDM accords?

    I would like the motor to run like it came from the factory so I feel like a chipped OBD-1 ECU with some kind of H23A map would be ideal for drivability and performance, but I would need an OBD-2 ECU to pass inspection. From what Ive read here the best option seems like a PCD ECU with a VAFC, but how efficient do you think that ECU is at running the H23A? Let me know what you think, I'm pretty much trying to make the car seem like it rolled out of the factory with this motor, probably going to go with either v6 accord oem exhaust or tl-s cl-s mufflers, and I plan on using the JDM OEM air filter.
     
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