Need new ECU

[redchicken]

Hi guys so it appears my ECU maybe stuffed in my 2000 nb mx5, is there a plug and play replacement that will give a little more power or should I just replace with a stock secondhand or new ECU, any feedback appreciated
Michael

[greenMachine]

COW alert!

I am not going to buy into the debate, but beware plugging in just a new (stock) ECU.

I am not sure about an NB8A, but in the NB8B it needs to talk to your immobiliser unit, which needs to talk to the key reader ring on the ignition lock, and it all needs the right signal from your key's transponder. I need to check my PMs, as I sold some NB8A electronics (ECU, ignition switch, keys, locks amongst other stuff) to someone who needed a new ECU to fix a problem with his old one. Most of this was to address getting the ECU to work in another NB8A, and my PMs may shed more light on just what was required and why; I'll have a look and let you know.

The above is irrelevant if you go aftermarket ECU.

[redchicken]

Hi to be clearer the car is a nb8a pre October 2000 model.

[StanTheMan]

well.

you might be able to get an OEM ECU.....It may be problematic if you need a key but it will be cheaper than an aftermarket ECU by a long way

MS3 PnP will cost you about $1700 landed
150-300 for a WB 02 sensor
then you will need another $800 to have it tuned
you need to budget for $2500
you may or may not need the WB 02 if its getting tuned by a pro

but really do you want an aftermarket ECU without having all the other bolt on bits?

exhaust
intake.
some extra engine bling
You're almost half way to an engineered turbo. drive in drive out.

[redchicken]

Thanks for the reply mate
Do you know how much for an Oem ECU ?

[GR124]

I have a NB8A year 2000 (not sure of the month ATM). Yep the thing has an immobilizer with the ring around the key barrel.

[StanTheMan]

Thanks for the reply mate
Do you know how much for an Oem ECU ?

yoiu need to find out if the key needs programming.It should be possible. I know mazda charge a decent amount for peeps who have had to replace keys.

in which case you would pick up a 2nd hand one, for not much(obvious reasons) tow your car to mazda and have Mazda reprogram the current key you have.
Nitro Dann converts cars all the time. Surely he would know where a few of these ECU are....if they are not collecting dust in his workshop.
perhaps he may even have a better solution

if you pick up a ECU together with the matching key you would then have to have the barrel on the steering wheel redone and put up with a different key
to start the car. Or you go the whole hog & buy a new lock set.... ( no don't do that)
are you sure its your ECU? What makes you think its toast?

[hks_kansei]

I believe that the Japanese NB8A didn't have an immobiliser, so if you can get an ecu from one it should skip the whole matching key saga.

Price wise, oem ones secondhand tend to be fairly cheap, $150 max, but usually a lot less.


Aftermarket ecus allow tuning etc, and more power (since you can tune to suit any mods you add)
However, There's usually more to it than just plug in and go, you'll normally need/want a wideband o2 sensor, and an air temp sensor. Then obviously you'll need to tune the lot to run properly. (Or pay a pro to do it)

[Mr Morlock]

all the foregoing guys / posts know far more than I do about ECU's but you have had a lot of problems with this car. What brings you to the conclusion that something is wrong with the ECU. You really need to get sorted with some mechanics / workshops that can trouble shoot. Getting prices on anything can be done by you- i.e. ring/ e mail etc. Mazda can tell you the price for an ECU- thats simple or at least should be but dont buy by just taking a punt. The MX-5 of its era runs the same l sort of control units as other cars so a competent mechanic can do checks and they can get prices- and then you decide.

[93_Clubman]

DTH faced a similar issue earlier this year - here's his posts: search.php?author_id=14739&sr=posts

[93_Clubman]

DTH faced as similar issue in terms of NB8A ECU replacement earlier this year - this was DTH's specific thread: viewtopic.php?f=55&t=74645
Some ADM NB8A had a immobiliser, in which case they need to be treated as per ADM NB8B. Easiest work around, as indicated by hks_kansei, is probably a JDM NB8A ECU as they didn't have an immobiliser. $50-$100 for a NB8A ECU.
But as others have already indicated above, be as sure as you can possibly be that your ECU is actually the problem.

[mx589]

All nb Aus delivered mx5s 1998 -2005 have the immobilizer standard with a chip built into the key.
The Ecu immobilizer unit and key are all a matched pair, like others have said in here.
If you need a good working matching ecu immobilizer unit and key send us a private message.

[greenMachine]

DTH is the person I sold my ecu etc to, I have PM'd him but he hasn't read it yet. That was case of the ecu, immobiliser etc not being required, as a result of a 'left-field' solution solving his problem.

[StanTheMan]

left field?

is that like removing the passenger air bag?

[manga_blue]

Alternatively, you can go to somewhere like Jaycar, buy a pressure pak of electronic circuit board cleaner, take out your exisiting ECU, remove the back and front covers and totally drench it with the cleaner, especially the plug holes. Do the plugs on the loom that go into the ECU as well. Let it all dry for half a day and if you're lucky you may find it'll be good for another 10 years or so.