I want to swap my 1.8 for a 2.5 but how

  • i have read a lot of posts on this site and others about swaping a 1.8 mx3 engine with obd 1 with a klde or klze and a few about using a mx3 with obd 2 but the more i read the more i get confused they seem to contradict each other.

    i have a 1.8 mx3 with obd 2 and want to swap the engine with a klde out of a probe or mx6 as they are easy to get

    now the most detailed posts are about obd1 could someone tell what are likly to be the propblems with ob2, i have read some where that an engine swap in a obd2 car wont pass the emissions test is this true.

    one post i have read for a obd2 car and klde engine said too
    use klde air flow meter and k8 ecu and k8 ignition (dizzy i think)
    is this right

    any help would be great


  • assuming this setup will run the engine

    use klde air flow meter and k8 ecu and k8 ignition (dizzy i think)

    i know the vris valves will open at the wrong time i had a probe a few years ago and i think vris 1 opens when the engine starts and 2 opens at 3000 rpm or something like that. i belive the vris valves are controlled by engine rpm and i have played with microprocessers before and it would be easy to make one read the rpm from the crank sensor and open the virs valves at the right time itself. but what other problems might there be in perticular for the emissions test

    any help would be great thanks

  • Not sure about the obd issue as my conversion is obd1, but you will need k8 dizzy, klde AFM, it would be better to get the klde ecu too, especially from the donor engine if possible, you can run the klde on the k8 ecu too but it may run the car richer or opposite

  • if i brought a mx6/ford probe could i take the wire loom out put it in my mx3 and just use the klde engine with its own afm ecu and dizzy

    would there be amy problems putting the wire loom in a mx3

  • you use the loom from your mx3, plug and play!! when i done my conversion I got most of the loom that I could from car that the donor engine came from, this came in handy as some of the mx3 loom needed extending so I used mx6 loom to do this, you can use either a k8 or klde dizzy, you need definatley need klde AFM and ecu

    EDIT I'm only going on the basis of OBD1 conversion, not sure about OBD2

  • PM the admin they can tell you all the problems with the OBD2 swap, i remember reading its a nightmare, even suggesting that you only buy a pre-96 mx-3 as these are OBD1.

    Hope not, for your sake!

  • @546f75276b=barrywhite21:

    PM the admin they can tell you all the problems with the OBD2 swap, i remember reading its a nightmare, even suggesting that you only buy a pre-96 mx-3 as these are OBD1.

    Hope not, for your sake!

    Should get a 91 then u dont need to worrie about emmisions or obd2 problems ;)

  • @2a67d34702=DaveMc:


    PM the admin they can tell you all the problems with the OBD2 swap, i remember reading its a nightmare, even suggesting that you only buy a pre-96 mx-3 as these are OBD1.

    Hope not, for your sake!

    Should get a 91 then u dont need to worrie about emmisions or obd2 problems ;)

    Even better!

    Same as mine except mine is a 92 and emmisions still dont count :D :D

  • Mines a late 95, no cat, 2.5, and did very well in emissions.

    Regarding the whole OBD thing, have a read on mx-3.com. There's posts how all they had to do was use the kl02(klde) vaf with the OBDII loom and k8 ecu. I wish I could confirm this for UK but I know Daryll had a very hard time with an OBDII swap. You could always just get megaquirt, install it, get used to it, then do the swap.

  • Looking at a KLDE tomorrow so I'll chime in with a few questions. :)

    I've a 91 Eunos Presso regestered in the UK in 96 so do I need a cat?

    & is it the same for the MX6? IE I have to get a pre-91 for the OBD issues?

  • Never installed a KLDE but for the ZE

    The problem is with the OBDII loom, it will not accept an ECU that will run the Engine properly. The ONLY ECU that will fit the UK OBDII loom is the standard OBDII MX-3 K8 ECU.

    In the USA they have a completely different OBDII loom than we were given in the UK so what they do in the USA is not easily possible it the UK.
    (In USA they have a proper OBDII diagnostics port that they can plug a laptop into, and 4 oxygen sensors where in UK we have same OBDI diagnostics port and only 2 oxygen sensors)

    In the USA to get round this they use a KL02 VAF from the KLDE engine which leans out the fuel mix then they get a quality adjustable FPR (fuel pressure regulator) Plug their laptop in and adjust the fuel pressure until it is where they want it. To get the VRIS working correct they simply install switches to operate it. (google MX-3 KLZE MSD window switches)

    There have been a few done in the UK but they do not run as good as an ODBI swap with the correct ECU, personally I would not bother as they run like shit on the K8 ECU even with the fuelling kinda bodged for it to run a bit better. Personally its alot of hassle to go through for a car that in the end will still not be right.

    If my car was already modded in a way that I could not remove (bodykit etc) and I REALLY REALLY wanted to swap the engine then I would look at swapping in an OBDI loom, but its not just the engine loom you have to swap its the fuse bow loom and interior loom too! If you were an electrical wizz you might be ably to swap the engine loom which is easy and then there are about 15 wires left that go to the fusebox and interior loom that would need to be cut and re-arranged where they go into the ECU or you might be able to make up some sort of converter cable for those wires. Then you would need to disable/remove the immobiliser as it don't run on the OBDI loom and I don't think the airbag will either.

    If it was me and my MX-3 was bog standard then I'd honestly sell it and buy an OBDI MX-3 with a knackered engine and use the money I made to go towards buying the new engine.

  • Lori Carlyle

    To be honest as far as MOT is concerned as long as it passes the exhaust gas test then it does not matter if it has a CAT, unless you get a picky bastard! But I guess if you could prove it was a 91 then it would be fine.

    As for the engine there is only one difference really between the early and later engines and that was the number of Temp sensors it has. But you simply swap over the housing they plug into from the K8 engine onto the KLDE. Its a bit of a apin to do as the IM has to come off and the Fuel rails to get at it.

  • Nippon In DERBY will source a KLZE for you for £450 £550
    Mr Engines can get them too.

    Nippon will probably have one in stock, but they probably won't realise it you need to go there really and look.

    But as with all second hand engines its always a risk and the guarantee they give is usually worthless and hardly ever honoured!!

  • Right done some digging around about the KLDE swap as i've only done ZE swaps.

    If you have OBDI you simply use the Engine, KL03 VAF and an OBDI MX-6 or Probe ECU (Perferably take the whole lot from same car)

    Aparrently the ONLY ECU that will work on an OBDII MX-3 is the standard one that came with the car. Aparently OBDII MX-6 / Probe ones do not work but this is based on USA ODBII cars, so who knows?

    You still use the KL03 VAF

    So it looks like you will have to do like they do on OBDII KLZE swaps and run an FPR to adjust the fuelling and switches for the VRIS. But you will have no way of knowing when the fuelling is setup correct as it has no proper OBDII diagnostics port.

  • would it be possible to use the engine and the wire loom,ecu from an obd1 probe/mx6. would the obd1 wire loom fit in an mx3 obd2 car or are the two to diffrent

  • The engine loom will swap of coures but as I mentioned you need to swap the INTERIOR AND FUSEBOX looms!!!!

  • You can do anything if you know what your doing.

    Would it be plug and play? NO

    Read my previous posts they tell you whats needs to be done to change the loom!


    There are 3 main looms in an MX3:
    1. The Engine loom
    2. The interior loom (dashboard, heater comtrols, radio, also goes forward to the lights)
    3. The fuse box (kinda mixes with the interior loom)

    1. The Engine loom is easy to swap!! It goes through the bulkhead and attaches to the ECU, you simply unplug it and push it through the bulkhead. There is one wire that you have to undo from the fuse box.

    2. The Interior loom has about 15 wires that go into the ECU that are not it the right place for ODBI ECU. The interior loom also mixes with the Fusebox loom. So you also need to change that loom too. To change the Interior loom you need to remove your cars interior. By this I mean the dashboard doorcards, boot lining, carpet, everything!! Then because it goes through to the front lights etc you have to reomve the front bumper and the wings to get to all the wiring.

    Or as I said earlier instead of swapping the WHOLE interior and fusebox looms you could get both of the OBDI and OBDII ECU wiring diagrams (Pinouts they are called) and try and identify just those 15 wires on each Pinout. Then you could could basically cut the wires of the plug that goes to the ECU and splice them back on in the correct place for the OBDI Pinout.

    But don't forget as I also mentioned earlier ODBII cars had an immobiliser and OBDI cars did not. So there will be excess wiring there for the immobiliser that might need sorting out some how, or disabled or removed alltogether.

    There is also wiring for the AIRBAG, OBDI cars did not have an airbag, so you might have problems there too I don't know.


    So it really depends how daunting you find all that. You basically need to swap every wire to do it clean.

    If you have the time get 3 mates together and a couple of toolkits and go to a scrapyard and find an OBDI MX-3 and Strip it and take out all its wiring (you will do it in a day with 3 helpers). This will show you exactly what your up against and you will be able to see what wires go to the ECU and the loom should only cost £20 max as nobody usually bothers. Just remove every wire that has anything to do with the ECU, you will just have to follow them from the ECU and see where they go.

  • have a look at this link, 2nd product from bottom of page.


    love this site, and its recently been updated so even better!

  • I knew someone with the knowhow would do it eventually.

    Props to Garfy for the find!

    Link: http://www.xtremethings.com/Products.htm Second product from the bottom of the page.

    I am now offering adapters to convert your OBDII 96-97 KL cars to enable you to run your KLZE with a chipped computer. Now there is an option to get the full potential from your KLZE without having to change the engine harness or have an electrical engineering degree to install an aftermarket engine management unit.

    This adapter is 100% plug-n-play. You just remove your OBDII computer, install the adapter and a chipped OBDI ECU or other OBDI KL computer and you are ready to roll. One of the nicest things about this adapter is that when it comes time for emissions testing -simply pull the adapter and chipped ECU and then re-install the OBDII computer. No modifications to your car wiring are neccessary.
    I HOPE THIS WORKS WITH OUR LOOMS IN THE UK!!! AS THEY ARE DIFFErent to those found in the usa. so bear thisin mind. but it can be done!

  • Just noticed that this only does the Engine Loom which is dead easy to swap anyway.

    I have put an OBDI engine loom onto an OBDII car myself and can say 100% that it will not even try to start.

    I put this down to the immobiliser and ignition wiring also being different.

    So there is more to do than plug and play.


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