2 Problems with swap :(

  • admin


    As most of you know the ZE is in!

    So far I have been testing it on the old K8 ECU just to make sure it starts, so last night I plug in the new ECU (meant to be a KL-31 but the sticker is missing), I turn the car over and…... nothing!

    Does anyone know of any reason why it wouldnt do anything at all other then it being dead!??

    Tonight im going to clean up the pins as they are a bit dirty, also gona connect it and do a code check, but I would have thought that it still would have started :(

    The other problem I have is that the accelerator cable has way to much slack on it, any guys with ZE's on here - did you use the stock cable, or did you need to swap it or do something with it??

    Thanks for any help guys.


  • maybe you've got a ECU from a 2.0L KF engine from a 323F.
    Some of this has a chipped key.
    So you need the right key for it.

  • admin

    Hmm, is there any way to tell if I open the ECU and look on the board?

    If not then I will have to ring nippon spares & change it!!



  • Jono,

    I don't know how the 2l ecu with the chip key look like on the inside.
    A friend of mine had one for testing.

  • admin

    Ok I will try cleaning the pins first, as you never know, and trust me this ecu is very dirty on the outside,

    I will then try the codes, if I get nothing then its gona be a new one, if I get something then… well.. we will see!! lol


  • not sure excatly but i recall somone say about OBD 1 in pre 1994 mazda then OBD2 in newer. could be wiring. best ask tommy D

  • Yeah,

    All the ZE ecu's only work in OBD I MX-3's, but a 1994 should be OBD I.

    3. KL 2.5 swap

    The best thing about this swap is how easy it is to do. That said you need to buy an MX-3 that uses OBD-I (on board diagnostics version 1). If you want the swap to be easy, and let's face it, that is the whole point of this swap.

    I can see that a lot of you are probably thinking, what is OBD? How and why do I make sure I get the right version? –-->

    OBD Explained
    On Board Diagnostics is used by mechanics to check for faults with your car by plugging in a special diagnostics reader that will show a series of 'fault codes' that can then be looked up to determine any problems.

    Before 1995 most cars used OBD-I, and most manufacturers used their own special diagnostics reader. This meant that a garage would have to buy and learn how to use more than one reader. so in 1995 they brought out OBD- II, which was fitted to nearly all cars in the UK. OBD-II is universal which means you only need one diagnostics reader for all cars. It also has much more advanced diagnostic capabilities than OBD-I, but for the purpose of this swap it should be avoided unless you are a very competent Auto electrician with a lot of spare time on your hands-and I do mean a lot!

    ----> This is because on the MX-3 to accommodate for the OBD-II system they completely changed the cars wiring loom (all its electrical wires).

    This causes a problem for us, because to complete the KL engine swap you have to 1. Swap the engine over and 2. Swap the ECU over to match the engine.

    It is the ECU that causes the problem as there are only 2 ECUs that you should really use and they both are only compatible with the OBD- I wiring loom.

    So make sure you buy an OBD-I MX3 if you plan to do this swap. All MX-3s before 1995 are OBD-I and some early 1995s (made in 1994, released in 1995).

  • admin

    I am under the impression that OBD II has different connectors and so would not connect to the OBD I plugs, is this correct?


  • No thats not correct.

    You can tell what OBD you car is by counting the number of connectors going into the ECU. OBDII has 4 plugs. ( count where the main conectors go into, they are yellow / White I think, can't remember?? It just looks like one big connector but look closely and it is made up of either 2, 3 or 4 connectors)


    LOOK UNDER THE BONNET. The diagnostic connecter should be on the right hand side by the firewall if your looking at the car from standing in front of it. If its under the hood its OBDI.

    LOOK UNDER THE STEERING WHEEL BY YOUR FEET. If there is a diagnostic connector there than it is OBDII.

    This second method is not 100% reliable as some OBD II MX3's have in under the bonnet. But if its under the Dash then it is almost certainly OBDII.

  • It's also easy to install a klze into an obd2 mx-3, just need to run a different vaf, use the original ecu and install a fpr. We did quite afew already and they are still running strong!


  • whats fpr? :roll:

  • admin

    Well it looks like it was a dead ECU all along, but the company I got it from are gona swap it :D

    Just gota wait a few weeks for it to come in.


  • They should test this stuff before they send it out, you must be bummed mate. Congrats on the swap though, I'm well impressed. How long did it take in all?

  • good find but thats a kl55, and not the good one chipped or not. There are two ecus that work the best on the 2.5 klze, kl31 and kl36, the 36 has better vris points as the 31 has straight power curve and the 36 peaks at 4200rpms and 5500rpms. On ebay you will also find they sell POwer chips which you need to solder yourself…..please save your money, they dont work. The JE50 VAf is only needed on ODB2 cars as they came with a different VAF.

    when buying a kl31 or a kl36 you will have to remove the speed limiter by removing one of the pins or cutting one of the wires, otherwise you will find that your car will not go above 180kmph as this is the restriction on japanese cars. I got a diagram of the pin that must be removed, just send a pm :wink:


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