Immobiliser / No spark

Technical Area Electrics & ICE
1
  1. My model of MX-5 is: NA 1.8 1996
  2. I’m based near: Faversham
  3. I’m looking for technical help or recommendations on:
  4. I’m trying to figure out if I have an issue with the immobiliser or not, and if I do, what I can do about it.

The story so far…
I took the centre console and tombstone out in order to pull out the headlight adjustment wheel switch. I wanted to move this to one of the blank switches to the right of the steering wheel. So, I cut the connector, and added about 28inches of wire and reconnected both ends being careful to ensure the correct wires were connected. I did it all one at a time to make sure of this. I tested the adjustment wheel and it worked perfectly still so thats all good.
I then decided that as the sun was out, I’d move the car out of the garage to give me more room.
However, the car seemed to fire up for a short time and then cut out. It did this a few times and each the same result. I wondered if it was some kind of safety feature that required the hazard lights to be plugged in (???), so I moved the tombstone into place and plugged in the hazard/pop-up button. This time when trying to start it, it wouldn’t even fire up, Instead it just cranks over and over.
So, by now I’m starting to think the immobilser is kicking in. I tried dsconnecting and reconnecting the battery - same result. Event tried cutting the headlight adjustmentment wheel switch off in case i’d made a dodgy connection - same result.
I then decided I’d check the spark plugs. I pulled out the one closest to the front of the engine bay and asked the wife to try starting the car. No spark at all.
So, am I right in thinking the immobiliser is the culrpit?
I also tried a different key in case the transponder in it has failed.

The only other thing I’ve done to the car since driving it last was to give everything a spray of wd40 under the bonnet. I’m beginning to wonder if thats done more harm than good. And if it has, then maybe there’s a chance it might “dry out” (???) and kick back into life?

Thanks
Rob

2

This is an excellent electrical insulator!

WD40 was the salvation of the old Mini with its exposed distributor, and the WD40 waxy residue prevented the sparks etc from being shorted out by the rain and salt spray coming in through the front grill.

If any WD40 residue has got into sensitive low voltage connector contacts ( eg CAS, MAF, TPS, etc) then it MUST be thoroughly rinsed out with Isopropyl Alcohol eg Isoclene, and those previously contaminated contacts then cleaned and protected with an appropriate Contact Cleaner, eg Servisol Super 10

3

Id retrace my steps with whatever you removed in the car just to check connections have not been disturbed. There are some relays under the dash drivers side that are worth checking.

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4

What does the immobiliser light do when you turn the ignition on?

5

Thanks for the suggestions all.
I’ve got cans of isopropyl and super 10 on the way to me, so will be giving that a go.

As for retracting my steps, there aren’t that many that I haven’t already done.

And there is no immobiliser light. Not that the light doesn’t come on, but that there physically isn’t a light. I’m just presuming that it’s a factory fitted one.

To be honest, I think it’s the wd40. I’ll report back.
Thanks
Rob

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6

Just an FYI for anyone interested.

This is now fixed. Fairly sure the issue was simply down to the fact that I hadn’t yet plugged in the handbrake warning cable when I had the centre console out. Plugged it back in and the car then starts as per normal.

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