Replacement '97 Mazda Soho Onboard Computer

[Vitrolic]

Hi friends,

We purchased a 1997 Mazda Soho sometime last year and it has been an awesome little car, however, with the recent rains the onboard computer ended up being flooded.

Picture of model

After taking the Car to 2 repair shops and the Kempster Ford dealership (Durban), we have been told that the onboard computer is broken and we have to get a replacement onboard computer + 2 keys + fitting of new system which will in total cost ~R10 000. One third of what we paid for the car! After that we have been told by the dealership that these onboard computers aren't even made any more and they can't get us one.

So it seems like we have the following three options:

1) Try salvage a computer + set of keys from a scrap dealer (seems dodge)
2) Try replace the computer with a generic version (suggested by an electrician we spoke to)
3) Remove the fuel injection system which is linked to the computer and just replace it with a carburetor (~R5k). After that we'd also have to have a new immobiliser installed.

Just wanted to ask whether anyone has experienced or heard of a similar problem and whether they can offer me any advice. I am based in Durban.

Thanks,
Steve

 

[Gnome]

1) Try salvage a computer + set of keys from a scrap dealer (seems dodge)

This is the best option IMHO, the car will run as it had before. It is also the easiest to do because only parts need to be replaced, if the mechanic can't get it working he shouldn't be called a mechanic. Might even work out the cheapest. I don't know about Mazda but on an Opel you can get most ECUs ("computer") for ~R1K, add in the transponder and key set and it's around R2-2.5K total. Cheaper than option 2 or 3.

2) Try replace the computer with a generic version (suggested by an electrician we spoke to)

Been there, done that, hated it (I fitted a Dictator, what a POS)

Here is your first problem, the "generic" version (actually an aftermarket ECU) will need to be tuned by someone using a dyno. If they screw it up, your car will run like crap and have low fuel efficiency and performance. If he actually does a EXCELLENT job it'll run like it had with the original ECU fitted. There is so much theory around these ECUs but the long and short of it is that aftermarket ECUs (generics) aren't even on the same level, technologically, that the old 1994+ OEM ECUs are.

Second problem, many of these units don't support all the functionality supported by the standard ECU, so if you go for this option, you better make sure that the "generic" will support things like idle control (or else your idle will be totally messed up) and such basic functionality. You also need an alarm because stealing a car with a generic is easier than stealing a car with a carburetor (no joke, I could get that car started as fast as you could with the key).

3) Remove the fuel injection system which is linked to the computer and just replace it with a carburetor (~R5k). After that we'd also have to have a new immobiliser installed.

That is an option but make sure that the carburetor version is exactly the same engine but with a carb. Then it will run like the standard carb version. Else you have some half ass'd backyard jobbie and your only hope is that the mechanic actually gave a sh#t when he worked on your car.

 

[Vitrolic]

Thanks a lot for your advice!