NB MX5 crank no start (immobiliser)?

[lingolouis]

Hi guys,

I recently bought an NB MX5 (1998) and a few weeks ago it ran out of fuel, and since then it hasn't started back up because there is no spark from any of the spark plugs. It turns over absolutely fine but just doesn't start. I have changed the coilpack, ignition leads, spark plugs, crank sensor and the cam sensor; all with no luck, still no spark.

The other day I noticed an aftermarket LED near the cigarette lighter which was displaying solid red, so I followed the wire from the led and it took me to - what seems like - an aftermarket alarm system branded "Toad". Could this possibly be an immobiliser issue? The battery has gone flat a few times whilst I've been trying to solve the problem which could've enabled the immobiliser.

Whilst rummaging behind the dashboard I also found a little box on the drivers side, with a pink label that reads: "Lucas 25AS energising coil - NC30-67-5G2", is this something to do with the immobiliser?

Any help would be much appreciated. Thanks in advance!

[Mazda Mender]

Is there no fob? is she an import?
M-m

[drumtochty]

No she is not an import the car has the normal European Immobiliser unit as identified by the original poster.

Two problems here.

Either the standard immobiliser has failed. Th Lucas Immobiliser unit is matched to the keys and the ECU and all parts have to be changed as a set.

Or the TOAD aftermarket unit probably needs disarmed which would need a visit to a Toad dealer to sort that out.

Therefore two possible causes of the problem.

[Mazda Mender]

I see two systems fighting each other...why on earth have a aftermarket system when it as a built in system?...I have had that before where the two systems are under conflict....
Rip the toad system out first and let's see where we stand.
M-m

[graymattor]

I Agree with M-M rip out the toad system, it should be fairly easy to, but i assume at some point it will break a wire associated with starting that will need connecting back together. do you know what model the TOAD is? i have recently fitted a Toad Ai606 to my Eunos and have all the wiring diagrams etc. if the LED is linked to the Toad, red means it is armed so it will not work.

You haven't by any chance removed something from a key ring, or using a spare key etc? some immobilisers work on RF and without that key fob being near the ignition barrel it wont start, i also have this sort installed on my Eunos.

If you can get some more details and photos we could have a closer look, but it sounds like its linked to the TOAD and by the battery going flat its reverted to maybe factory settings, where before it may have been set to permanently disarmed or something similar

[drumtochty]

Most aftermarket alarm systems at those times were sold to get central locking and the problem of two immobilisers rears it's ugly head.

If there is a Toad Dealer or good auto electrician near the original poster it may be easier to have them have a look, then after that and assuming the wiring is put back together the correct way it can then be decided if it is the Lucas unit that is faulty as it came OEM with the car.

[Mazda Mender]

If you like the feature of remote C/L you can install that easy enough again with a great kit we use off the bay of E for the major sum of £20 odd once the toad system is removed, where are you out of interest?
M-m

[drumtochty]

You haven't by any chance removed something from a key ring, or using a spare key etc? some immobilisers work on RF and without that key fob being near the ignition barrel it wont start, i also have this sort installed on my Eunos.

If you can get some more details and photos we could have a closer look, but it sounds like its linked to the TOAD and by the battery going flat its reverted to maybe factory settings, where before it may have been set to permanently disarmed or something similar

Which is why in this instance I disagree with both Wayne and Greymattor. Before anyone rips anything out and we do not know what the original posters auto electric skills are, my first thoughts are to go to a TOAD dealer if the Op has one near him and if possible to get the alarm into the mode it was in and maybe get a new zapper. As greymatter has advised in his last sentance quoted above.

If on the other hand there is no useful local TOAD dealer around the OP, then it is a case of removing the TOAD system and then trying if he gets all the wires reconnected to see if he gets a spark at the plugs.

The Lucas immobiliser used by the factory and mentioned by the OP is a part that is failing on a regular basis on these cars.

As always guys it is a case of a few suggestions as no one gets it correct every time.

[Mazda Mender]

Toad is an aftermarket system...it"CAN" be removed without any interference in the the insurance side or the factory immobilliser, there are many places this owner can go to and use that would remove it with no issues besides a dealership.
That's why I asked which area...if he is close to me I'll rip it out, we need to start somewhere, a dealership is the last place I would recommend...
I would fully test everything any way before doing anything ....and I am well aware of the factory immobilliser issues....been doing them a long time to eddy.
M-m

[blackyb]

Bit confused her. Quote from original post stated.

"I recently bought an NB MX5 (1998) and a few weeks ago it ran out of fuel, and since then it hasn't started back up"

Reading this as written I take it the car was running till it ran out of fuel so up to that point it must have had a spark.

Refueled and now it wont start.

So what's been done in between the running out of fuel to fueled up or am I missing something or miss reading the original post.

[lingolouis]

Hi guys, thank you all for the responses, I have not replied in this topic until now because I wasn’t aware that my post had been approved. When I’m home from work I’ll comprise another post to try and add a bit more information.

Cheers guys.

[lingolouis]

I Agree with M-M rip out the toad system, it should be fairly easy to, but i assume at some point it will break a wire associated with starting that will need connecting back together. do you know what model the TOAD is? i have recently fitted a Toad Ai606 to my Eunos and have all the wiring diagrams etc. if the LED is linked to the Toad, red means it is armed so it will not work.

You haven't by any chance removed something from a key ring, or using a spare key etc? some immobilisers work on RF and without that key fob being near the ignition barrel it wont start, i also have this sort installed on my Eunos.

If you can get some more details and photos we could have a closer look, but it sounds like its linked to the TOAD and by the battery going flat its reverted to maybe factory settings, where before it may have been set to permanently disarmed or something similar

Hi mate, the model of the TOAD system is TOAD a51s (according to the back of the TOAD box). I'm 99% sure I've not removed anything which would effect the system, and I also don't have a second key.

I'm also 99% sure the LED is linked to the TOAD system; I followed the wire from the LED on the centre unit and it took me straight to the TOAD box. I will get some pictures tomorrow so you can have a look .

[lingolouis]

If you like the feature of remote C/L you can install that easy enough again with a great kit we use off the bay of E for the major sum of £20 odd once the toad system is removed, where are you out of interest?
M-m

Hi mate, I'd love the feature of remote C/L, what's the eBay kit called?

I'm located in Worcestershire .

[lingolouis]

Bit confused her. Quote from original post stated.

"I recently bought an NB MX5 (1998) and a few weeks ago it ran out of fuel, and since then it hasn't started back up"

Reading this as written I take it the car was running till it ran out of fuel so up to that point it must have had a spark.

Refueled and now it wont start.

So what's been done in between the running out of fuel to fueled up or am I missing something or miss reading the original post.

Hi mate, it was refuelled very shortly after it originally ran out so I guess it must just be a coincidence that something else when bust at the same time .

[lingolouis]

A little update; I ran the LED fault reader through the diagnosis box just to be sure, and got the code 1624. I did a quick search on Google and it told me it's indeed an immobiliser-related issue. I also read about a guy that had the exact same issue and received the exact same code; he reckons the code means 'immobiliser cannot read key'. He switched the ECU immobiliser & ignition and his car was running.

Any thoughts? Cheers guys .