[NC] Swap 2.0 in 1.8 MX5 NC

I’m looking into swapping a 2.0 into my 1.8 MX5 NC as my 1.8 bearings are dead. I can’t find a lot of information on the subject. What I’ve found so far:

  • 2.0 is a direct fit and is no more trouble to fit than and the same process as a 1.8
  • Besides the engine one also needs the 2.0 ECU and engine loom
  • The current instrument cluster has to be reprogrammed for the immobiliser or replace it with the cluster belonging to the replacement 2.0 ECU. So either 2.0 cluster with 2.0 ECU and FOBS or 2.0 ECU with reprogrammed 1.8 cluster and original fob.

Is the above correct and complete? Anything else I have to think of that’s different in fitting the 2.0?

You could get a lot of info from Roddison Motorsport


Thing is, I’m not from the UK and won’t have them do it as a consequence, feels a bit rude to ask for information and then having it done somewhere else?

I have contacted him and explained that I won’t be coming to his shop because I’m not from the UK but that I really can’t find any info on this besides what I already posted. He was very helpfull! He confirmed my information so now I can go and get myself a 2.0 :smiley:


Good news, good luck with the swap

Good luck with that project!

Good attitude and I’m sure that paid off.

Probably best to get a complete car with all the parts you need, preferably a runner so you can hear the engine, check for noises, smoke, etc.

If you are struggling to find an ecu set, cluster, etc, I probably have the one you need.

Good luck with it.  


Finally I have an engine and coming week my car will be shipped to a garage. I found some other interesting info on my journey and will share it when the swap is done so the story is complete.

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Hi Nippan, I trust your swap is going well. I’m considering doing the same swap and having just found your thread was hoping you might be able to provide some additional heads up. I have sourced all the engine, wiring loom and ECU and although I knew about the immobiliser/key issue finding someone to reprogram seems to be like finding rocking horse exhaust.
Any help you can offer greatly appreciated.

I have also been talking to Jeff (Nippan) about his swap and we have ironed out a couple of answers to known problems.

He left the 1.8 ECU in place to run the 2.0 engine but the 1.8 ECU cannot operated the VVC so an ECU change is needed at some stage to get the full benefit.

I have talked to Jeff about the speedo swap and the difficulties with the software and ODB adaptor.

I think I can see a road that I could follow for this conversion.


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Hi John,

As I mentioned above I have an engine, and wiring loom for this job and yesterday I bought a full lock set including the dash panel and ignition lock and key. The work is scheduled to start next Tue/Wed and predicted to take a day. How it will all work out remains to be seen however I am assured it shouldn’t be too difficult with all the parts to complete the jig-saw.

Once it’s done I’ll try and remember to post up how things went.

You don’t need to change the mechanical locks i.e. door and ign locks…

There is a roll pin holding the mechanical key in place that you can see when its half flipped open.

The shell of the key contains the id and the remote electronics that match the ECU and speedo.

As long as the key rotates the lock, and the shell is within 10-20 mm of the ign lock the id chip will be seen and the immobiliser will turn off.

I trust the ECU is a match for the engine spec if the Engine has VVC, the ECU needed to have been on a VVC engine before or the VVC map is empty and missing a link to operate the VVc valve.

Let us know how you get on if you win I guess we all win.


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Just read your post again you should also have the immobiliser relay normally mounted by the drivers foot without that the ECU will not allow it to fire up.

The speedo, ECU and immobiliser are all coded to work together and nothing will happen if one is wrong ie not matched.

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John, you seem to have a good understanding of these issues! See link below to see what was included in the kit I bought yesterday and arrived today:


I’m not particularly well versed in the black art of electronics and leave it to others who no better than me. I understand your comments but am unable to ID the part which you mention. If you have time have a look and see what was provided from PMS who specialise in these cars amongst others.

Feedback appreciated.

Hi archie. What do you want at the end of the swap? If you:

  • don’t care about the mileage on the cluster
  • have 2 keys with the 2.0 cluster/ecu
  • have both the 2.0 ecu and cluster

then the easiest thing would be to swap ecu and cluster and switch mechanical keys to your new 2.0 transponder. If you know someone to change the mileage it would be even better. I have the following problem.

  • Got only 1 key with ecu/cluster set
  • Want to keep original mileage
  • Want 2 working keys
  • Cluster is UK but I’m on mainland Europe, meaning I need counting of distance in km’s

For now I see 3 options. Option is 1:

  • Getting my current keys programmed for use with 1.8 cluster and the 2.0 ECU
  • Swap rpm instrument face by hand from 2.0 ECU

Option 2 is:

  • Use 2.0 ECU and cluster
  • Program my current keys into 2.0 ECU
  • Get 2.0 cluster mileage adjusted
  • Get 2.0 cluster to count in km’s

Option 3 is to have the immobiliser removed from the 2.0 ECU with ECUTek, someone on miata.net said that can be done. I have, however, emailed at least 7 ECUTek dealers but only one responded that they don’t have Mazda software, heard nothing of the others…

I’m talking to eaa53 to see if we can come up with a solution but it’s a complicated matter…

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Apologies for slow response gents.

Indeed it is a complicated matter! And it seems not as easy to resolve as we might have hoped for.

I spoke with Paul Roddison last Thursday and his solution which in his words would be the easiest and cheapest for me, would be to buy the Instrument Cluster, ECU, Ignition lock set etc. The other option was for him to reprogram the the security PCU and key set but that would be in the hundreds of pounds due to him having to recover his outlay for the official Mazda equipment which issues and logs on their systems and provides the unlock codes for the software etc.

I chose the obtain my own and did so from a company found on google if you type PMS ltd for a total of £106 shipped and arrived on Friday last week. Included were as can be seen on their website under parts.(Mods I hope this is not in breach of the rules) if so please remove.

John, not sure how this fits with your points about the key and roll pin although I do understand what you mean about the key as I have had mine apart as it is falling apart and needs replacing and I do know the transponder can be swapped over to another key. That said though and with a full lockset I’m inclined to swop them over and be done with it rather than messing with the ECU and Instruments Cluster which is included.

My plan initially was to do everything myself however the seller of my new engine has their own business and offered a remove and fit for a very reasonable price to the point that it just didn’t make sense for me to do it all again. So my car will be in next Tue and hopefully return next Wed or Thu all going well.

I’m not sure if this info helps but we are all on the same journey and it there is anything I can do or offer in the way of help just shout.

Sounds like good progress, hope it’s all sorted soon

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Hi All,

All went well with engine swap from 1.8 to 2.0l with VVT and car collected this morning with a very sweet running engine. To make the change over the engine wiring loom had to be changed and incorporate the Purge Solenoid(valve) that the 1.8l does not have. In addition, the following were required. ECU, Instrument panel, ignition switch, Drivers door lock, Boot lock and to cap it all off being really OCD the glove box and cubby box behind the seats.

Engine out and replacement in in 1 day, finessing 2nd day with run up to temp and collected today. Interior trim refitted on return home job done and jobs a good-un. The Purge Valve, was the only stumbling block.

The guys at Steel City know their onions and I can’t thank them enough for very fair pricing for a totally refreshed low mileage engine fitted in a quarter of the time it would have taken me. Very impressed and if the read this Thanks Stephen, Rob and John.

I would also like to say thanks to the guys on here who took and interest and advice on some aspects where my knowledge is lacking. Thanks.

If anyone needs ECU,Dash,Lock set I have them all for 1.8 and 2.0l for very reasonable price just shout.


Great news, well done. You can now enjoy the driving

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