Hello!
I’ve just picked up a very cheap MX5, a Mk1 1.6 auto which was supposedly a non runner with a seized engine?
Back in the mid ‘90s I had a few new MX5’s but I haven’t had one since and have been toying with the idea of picking up a Mk1 as a bit of a toy/project.
I was looking for a 1.8 manual which is what I had previously but, this 1.6 auto came up relatively local and was ridiculously cheap so I had a quick punt.
Apparently the car had stopped driving and when looked at by the AA man, the previous owner was informed that the engine had seized, hence them selling the car.
The car arrived yesterday and at quick glance, it seems pretty good. It’s still in MOT and everything electrical works fine with the exception of the passenger electric window.
I tried to start the car and, as expected, didn’t start but, it did half turn over which surprised me as it was apparently seized?
I don’t know much about autos but I somehow remembered something about a switch on the gearbox on autos that if it fails, prevents it starting?
So, I put it into neutral and tried to started. It started first flick of the switch!
I then put it into D and it drove forward, R and it went backwards!
So, I’m guessing there must a switch of some description causing this fault?
Can anyone shine any light on this issue and offer advice on how to resolve?
Cheers in advance!
I know @Scottishfiver has more than a working knowledge of the NA Auto so tagging him.
Oh and welcome by the way 
Yes, there is a cable that runs from the auto gear selector to the ignition. This cable pulls a lever(only fitted to auto ignitions) that stops the car starting in anything other than neutral. This is a physical rather than electrical, stopping the igntion turning with the key.
If your key is turning and starter engaging the issue lies elsewhere
I had read about this cable but, I had discounted it as it didn’t seem likely to be the fault.
From what I have read, and I may have got the wrong end of the stick, it could be the inhibitor switch which may give similar symptoms?
Also, as an aside, where’s the best place to quality new parts? Are the cars well catered for at the main dealers or, is it a case of using specialists?
I want to give the car a good service, etc.
I thought autos start in Park.
Autolinkuk and MX5Heaven (google them) are probably best for used parts, though I perceive that some parts for the Mk1 are getting a bit thin on the ground.
I can start mine in neutral, but I cannot move it out from N until I switch off, go to P as usual.
Cannot really help the OP as apart from a pipe leak, I’ve not had to touch mine in 15 years.
Furthermore, my box is an 1840cc…I’ve a feeling the 1600’s are a bit different.
The inhibitor switch is a good shout but nothing on autolink as far as I can see. Last time I looked they were listed for both 1.6 and 1.8.
Not sure if a faulty inhibitor switch would cause complete non start and how you can test.
I’m guessing that this is the part?
I’ve ordered a Haynes manual to see if I can get to it and if it’s an easyish job?
I’d dig a bit deeper Mike before shelling £101 out on that.
Chasing issues with bits can get expensive and frustrating.
It may be, if you have a tame mechanic with a lift to check it above and below…that might be best. See if you can trace a local Auto specialist as well.
It may be , more simply, a bush failure…they do go.
It’s just a cheap plastic thingly in the shift assembly.
Hi there, possibly had/have a similar problem
see this
I’m currently awaiting better health and weather to look at the inhibitor switch
I also have a haynes manual and another maintenance guide. I’ll look in them in the morning to see if I can give you any pointers
That is the part and as price much higher than remembered and all versions out of stock we can reach our own conclusions.
Not an easy job but do-able.
With the symptoms as above limit the amount of potential issues with the ‘park’ issue?
I was hoping that as it started fine in Neutral and then could be driven fine with gear selection, it would limit the potential issue or, am I being a little optimistic?
From memory I think there is a cable from the ignition switch that prevents the gear selector from being moved, unless the key is in the ignition. There is then an inhibitor on the gearbox that only completes the 'electrical; circuit to the starter if the selector is in P or N. It;s possible the circuit for P in your case is bad (bad switch,connector ).
The switch is accessible from underneath the car but I believe access is limited and difficult (lift needed maybe)
Ok, thanks for that.
I bought an MX5 Haynes manual for it at the beginning of the week which arrived yesterday, only for me to find it doesn’t cover the auto box models.
I take it the Miata manual does?
Just remembered the good old Mellens stuff.
http://www.mellens.net/mazda/mazda_miata_extra_manual/1990_1994_auto_transmission.pdf
Ok, I’ll have a look at the Haynes and see if I can work out how to get the gear-lever trim off and check in there first.
Hi there,
Have a look here, sorry for the poor image but it may be of help
https://btcloud.bt.com/web/app/share/invite/XYUelIGKqQ
Definitely sounds like the isolator meant to only allow start when P or N has failed. Over years of driving autos its fairly rare, but the most common fault on an auto box, especially the proper sludgematics without electronics to add a level of uncertainty.
Years ago (early 70s) my Dad’s Triumph 2000 Auto stopped starting as we were on the A30 through Virginia Water (pre-M3). The garage instantly diagnosed the isolator, but as it was Saturday no chance of a BL part. By passing the isolator with one of the mechanic’s bootlaces (the only suitable wire available in the garage!!!), Dad was warned to make sure it was in P or N as otherwise it would start up in any gear position. Drove fine like that for a few weeks until BL dealer finally managed to get the part in and fit. Possibly under warranty as it was newish at the time…ah the good old days!
After buying the MX5 Haynes manual and finding it doesn’t cover the import versions/auto boxes I’ve now bought a Miata one which should hopefully be here midweek so in the meantime I’m going to do a bit of prep for a hood change and get it jacked up in the air ready to crawl underneath to diagnose the gearbox issues.
Rod Grainger/Veloce manual covers Eunos Roadsters.